From b2dbd528be351b6a57d848a2615daa08883c04f2 Mon Sep 17 00:00:00 2001
From: Olli Meier <hallo@olli-meier.de>
Date: Wed, 22 Jan 2025 15:55:55 +0100
Subject: [PATCH] use gsLayer.layerId for layerName + update fontra
 referenceFont

---
 src/fontra_glyphs/backend.py                  |   2 +-
 .../glyphs/A^1.json                           | 158 ++--
 .../glyphs/Adieresis^1.json                   |  28 +-
 .../glyphs/V^1.json                           |  88 +--
 .../glyphs/_part.shoulder.json                | 592 +++++++-------
 .../glyphs/_part.stem.json                    | 148 ++--
 .../GlyphsUnitTestSans3.fontra/glyphs/a.json  | 738 +++++++++---------
 .../glyphs/a.sc.json                          | 162 ++--
 .../glyphs/adieresis.json                     |  26 +-
 .../glyphs/dieresis.json                      | 132 ++--
 .../GlyphsUnitTestSans3.fontra/glyphs/h.json  |  18 +-
 .../GlyphsUnitTestSans3.fontra/glyphs/m.json  |  24 +-
 .../GlyphsUnitTestSans3.fontra/glyphs/n.json  |  18 +-
 13 files changed, 1067 insertions(+), 1067 deletions(-)

diff --git a/src/fontra_glyphs/backend.py b/src/fontra_glyphs/backend.py
index 612f014..05152ca 100644
--- a/src/fontra_glyphs/backend.py
+++ b/src/fontra_glyphs/backend.py
@@ -246,7 +246,7 @@ async def getGlyph(self, glyphName: str) -> VariableGlyph | None:
                 sourceName = f"{masterName} / {gsLayer.name}"
             else:
                 sourceName = gsLayer.name or masterName
-            layerName = f"{sourceName} (layer #{i})"
+            layerName = gsLayer.layerId
 
             location = {
                 **self.locationByMasterID[gsLayer.associatedMasterId],
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/A^1.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/A^1.json
index 40363e9..13dbe9a 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/A^1.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/A^1.json
@@ -3,63 +3,63 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 733,
+"x": 617,
 "y": 0
 },
 {
-"x": 555,
+"x": 412,
 "y": 700
 },
 {
-"x": 205,
+"x": 248,
 "y": 700
 },
 {
-"x": 20,
+"x": 40,
 "y": 0
 },
 {
-"x": 253,
+"x": 134,
 "y": 0
 },
 {
-"x": 356,
-"y": 470
+"x": 313,
+"y": 610
 },
 {
-"x": 385,
-"y": 470
+"x": 342,
+"y": 610
 },
 {
-"x": 491,
+"x": 521,
 "y": 0
 }
 ],
@@ -68,85 +68,82 @@
 {
 "points": [
 {
-"x": 600,
-"y": 268
+"x": 514,
+"y": 269
 },
 {
-"x": 162,
-"y": 268
+"x": 150,
+"y": 269
 },
 {
-"x": 154,
-"y": 103
+"x": 148,
+"y": 178
 },
 {
-"x": 596,
-"y": 103
+"x": 510,
+"y": 178
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 753,
+"xAdvance": 657,
 "anchors": [
 {
 "name": "bottom",
-"x": 377,
+"x": 329,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 678,
+"x": 591,
 "y": 10
 },
 {
 "name": "top",
-"x": 377,
+"x": 329,
 "y": 700
 }
 ]
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 548,
+"x": 733,
 "y": 0
 },
 {
-"x": 321,
-"y": 700,
-"attrs": {
-"name": "Hello World"
-}
+"x": 555,
+"y": 700
 },
 {
-"x": 275,
+"x": 205,
 "y": 700
 },
 {
-"x": 45,
+"x": 20,
 "y": 0
 },
 {
-"x": 65,
+"x": 253,
 "y": 0
 },
 {
-"x": 289,
-"y": 679
+"x": 356,
+"y": 470
 },
 {
-"x": 307,
-"y": 679
+"x": 385,
+"y": 470
 },
 {
-"x": 527,
+"x": 491,
 "y": 0
 }
 ],
@@ -155,82 +152,85 @@
 {
 "points": [
 {
-"x": 467,
-"y": 225
+"x": 600,
+"y": 268
 },
 {
-"x": 128,
-"y": 225
+"x": 162,
+"y": 268
 },
 {
-"x": 123,
-"y": 207
+"x": 154,
+"y": 103
 },
 {
-"x": 472,
-"y": 207
+"x": 596,
+"y": 103
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 593,
+"xAdvance": 753,
 "anchors": [
 {
 "name": "bottom",
-"x": 297,
+"x": 377,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 548,
-"y": 0
+"x": 678,
+"y": 10
 },
 {
 "name": "top",
-"x": 297,
+"x": 377,
 "y": 700
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 617,
+"x": 548,
 "y": 0
 },
 {
-"x": 412,
-"y": 700
+"x": 321,
+"y": 700,
+"attrs": {
+"name": "Hello World"
+}
 },
 {
-"x": 248,
+"x": 275,
 "y": 700
 },
 {
-"x": 40,
+"x": 45,
 "y": 0
 },
 {
-"x": 134,
+"x": 65,
 "y": 0
 },
 {
-"x": 313,
-"y": 610
+"x": 289,
+"y": 679
 },
 {
-"x": 342,
-"y": 610
+"x": 307,
+"y": 679
 },
 {
-"x": 521,
+"x": 527,
 "y": 0
 }
 ],
@@ -239,41 +239,41 @@
 {
 "points": [
 {
-"x": 514,
-"y": 269
+"x": 467,
+"y": 225
 },
 {
-"x": 150,
-"y": 269
+"x": 128,
+"y": 225
 },
 {
-"x": 148,
-"y": 178
+"x": 123,
+"y": 207
 },
 {
-"x": 510,
-"y": 178
+"x": 472,
+"y": 207
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 657,
+"xAdvance": 593,
 "anchors": [
 {
 "name": "bottom",
-"x": 329,
+"x": 297,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 591,
-"y": 10
+"x": 548,
+"y": 0
 },
 {
 "name": "top",
-"x": 329,
+"x": 297,
 "y": 700
 }
 ]
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/Adieresis^1.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/Adieresis^1.json
index f276d95..c8db159 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/Adieresis^1.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/Adieresis^1.json
@@ -3,28 +3,28 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "components": [
 {
@@ -33,15 +33,15 @@
 {
 "name": "dieresis",
 "transformation": {
-"translateX": 110,
-"translateY": 210
+"translateX": 128,
+"translateY": 220
 }
 }
 ],
-"xAdvance": 753
+"xAdvance": 657
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "components": [
 {
@@ -51,14 +51,14 @@
 "name": "dieresis",
 "transformation": {
 "translateX": 110,
-"translateY": 230
+"translateY": 210
 }
 }
 ],
-"xAdvance": 593
+"xAdvance": 753
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "components": [
 {
@@ -67,12 +67,12 @@
 {
 "name": "dieresis",
 "transformation": {
-"translateX": 128,
-"translateY": 220
+"translateX": 110,
+"translateY": 230
 }
 }
 ],
-"xAdvance": 657
+"xAdvance": 593
 }
 }
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/V^1.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/V^1.json
index efdba8b..8130455 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/V^1.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/V^1.json
@@ -3,63 +3,63 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 733,
+"x": 617,
 "y": 700
 },
 {
-"x": 491,
+"x": 521,
 "y": 700
 },
 {
-"x": 385,
-"y": 230
+"x": 342,
+"y": 90
 },
 {
-"x": 356,
-"y": 230
+"x": 313,
+"y": 90
 },
 {
-"x": 253,
+"x": 134,
 "y": 700
 },
 {
-"x": 20,
+"x": 40,
 "y": 700
 },
 {
-"x": 205,
+"x": 248,
 "y": 0
 },
 {
-"x": 555,
+"x": 412,
 "y": 0
 }
 ],
@@ -67,102 +67,102 @@
 }
 ]
 },
-"xAdvance": 753
+"xAdvance": 657
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 548,
+"x": 733,
 "y": 700
 },
 {
-"x": 527,
+"x": 491,
 "y": 700
 },
 {
-"x": 307,
-"y": 21
+"x": 385,
+"y": 230
 },
 {
-"x": 289,
-"y": 21
+"x": 356,
+"y": 230
 },
 {
-"x": 65,
+"x": 253,
 "y": 700
 },
 {
-"x": 45,
+"x": 20,
 "y": 700
 },
 {
-"x": 275,
+"x": 205,
 "y": 0
 },
 {
-"x": 321,
-"y": 0,
-"attrs": {
-"name": "Hello World"
-}
+"x": 555,
+"y": 0
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 593
+"xAdvance": 753
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 617,
+"x": 548,
 "y": 700
 },
 {
-"x": 521,
+"x": 527,
 "y": 700
 },
 {
-"x": 342,
-"y": 90
+"x": 307,
+"y": 21
 },
 {
-"x": 313,
-"y": 90
+"x": 289,
+"y": 21
 },
 {
-"x": 134,
+"x": 65,
 "y": 700
 },
 {
-"x": 40,
+"x": 45,
 "y": 700
 },
 {
-"x": 248,
+"x": 275,
 "y": 0
 },
 {
-"x": 412,
-"y": 0
+"x": 321,
+"y": 0,
+"attrs": {
+"name": "Hello World"
+}
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 657
+"xAdvance": 593
 }
 }
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.shoulder.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.shoulder.json
index a3af0c3..83aafd6 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.shoulder.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.shoulder.json
@@ -17,14 +17,14 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Light / NarrowShoulder",
-"layerName": "Light / NarrowShoulder (layer #3)",
+"layerName": "50EFFDD5-7E17-4ADC-BBC9-E16AAD6631DE",
 "location": {
 "Weight": 17,
 "shoulderWidth": 0
@@ -32,7 +32,7 @@
 },
 {
 "name": "Light / LowCrotch",
-"layerName": "Light / LowCrotch (layer #4)",
+"layerName": "7C8F98EE-D140-44D5-86AE-E00A730464C0",
 "location": {
 "Weight": 17,
 "crotchDepth": -100
@@ -40,14 +40,14 @@
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Regular / NarrowShoulder",
-"layerName": "Regular / NarrowShoulder (layer #5)",
+"layerName": "595FDB8C-ED41-486A-B76A-0FEFEF8BCDD1",
 "location": {
 "Weight": 90,
 "shoulderWidth": 0
@@ -55,7 +55,7 @@
 },
 {
 "name": "Regular / LowCrotch",
-"layerName": "Regular / LowCrotch (layer #6)",
+"layerName": "65575EEB-523C-4A39-985D-FB9ACFE951AF",
 "location": {
 "Weight": 90,
 "crotchDepth": -100
@@ -63,14 +63,14 @@
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 },
 {
 "name": "Bold / NarrowShoulder",
-"layerName": "Bold / NarrowShoulder (layer #7)",
+"layerName": "D607B100-382C-478B-A297-2EF174C3A363",
 "location": {
 "Weight": 220,
 "shoulderWidth": 0
@@ -78,7 +78,7 @@
 },
 {
 "name": "Bold / LowCrotch",
-"layerName": "Bold / LowCrotch (layer #8)",
+"layerName": "BA4F7DF9-9552-48BB-A5B8-E2D21D8D086E",
 "location": {
 "Weight": 220,
 "crotchDepth": -100
@@ -86,423 +86,423 @@
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 162,
-"y": 401
+"x": 131,
+"y": 409
 },
 {
-"x": 250,
-"y": 229
+"x": 167,
+"y": 246
 },
 {
-"x": 250,
-"y": 268,
+"x": 167,
+"y": 355,
 "type": "cubic"
 },
 {
-"x": 259,
-"y": 283,
+"x": 203,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 284,
-"y": 283,
+"x": 277,
+"y": 402,
 "smooth": true
 },
 {
-"x": 295,
-"y": 283,
+"x": 315,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 304,
-"y": 280,
+"x": 345,
+"y": 390,
 "type": "cubic"
 },
 {
-"x": 310,
-"y": 276
+"x": 365,
+"y": 370
 },
 {
-"x": 310,
+"x": 365,
 "y": 0
 },
 {
-"x": 530,
+"x": 455,
 "y": 0
 },
 {
-"x": 530,
-"y": 448
+"x": 455,
+"y": 423
 },
 {
-"x": 490,
-"y": 478,
+"x": 425,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 430,
-"y": 501,
+"x": 380,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 357,
-"y": 501,
+"x": 294,
+"y": 490,
 "smooth": true
 },
 {
-"x": 259,
-"y": 501,
+"x": 205,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 209,
-"y": 461,
+"x": 170,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 188,
-"y": 401
+"x": 155,
+"y": 409
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 560,
+"xAdvance": 528,
 "anchors": [
 {
 "name": "_connect",
-"x": 250,
+"x": 167,
 "y": 0
 },
 {
 "name": "connect",
-"x": 530,
+"x": 455,
 "y": 0
 }
 ]
 }
 },
-"Bold / LowCrotch (layer #8)": {
+"50EFFDD5-7E17-4ADC-BBC9-E16AAD6631DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 162,
-"y": 371
+"x": 102,
+"y": 384
 },
 {
-"x": 250,
-"y": 199
+"x": 117,
+"y": 266
 },
 {
-"x": 250,
-"y": 251,
+"x": 117,
+"y": 410,
 "type": "cubic"
 },
 {
-"x": 259,
-"y": 283,
+"x": 173,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 284,
-"y": 283,
+"x": 252,
+"y": 463,
 "smooth": true
 },
 {
-"x": 295,
-"y": 283,
+"x": 292,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 304,
-"y": 280,
+"x": 335,
+"y": 437,
 "type": "cubic"
 },
 {
-"x": 310,
-"y": 276
+"x": 364,
+"y": 408
 },
 {
-"x": 310,
+"x": 364,
 "y": 0
 },
 {
-"x": 530,
+"x": 381,
 "y": 0
 },
 {
-"x": 530,
-"y": 448
+"x": 381,
+"y": 414
 },
 {
-"x": 490,
-"y": 478,
+"x": 347,
+"y": 450,
 "type": "cubic"
 },
 {
-"x": 430,
-"y": 501,
+"x": 303,
+"y": 479,
 "type": "cubic"
 },
 {
-"x": 357,
-"y": 501,
+"x": 252,
+"y": 479,
 "smooth": true
 },
 {
-"x": 259,
-"y": 501,
+"x": 169,
+"y": 479,
 "type": "cubic"
 },
 {
-"x": 209,
-"y": 461,
+"x": 132,
+"y": 429,
 "type": "cubic"
 },
 {
-"x": 188,
-"y": 371
+"x": 121,
+"y": 384
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 560,
+"xAdvance": 501,
 "anchors": [
 {
 "name": "_connect",
-"x": 250,
+"x": 117,
 "y": 0
 },
 {
 "name": "connect",
-"x": 530,
+"x": 381,
 "y": 0
 }
 ]
 }
 },
-"Bold / NarrowShoulder (layer #7)": {
+"595FDB8C-ED41-486A-B76A-0FEFEF8BCDD1": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 162,
-"y": 401
+"x": 131,
+"y": 409
 },
 {
-"x": 250,
-"y": 229
+"x": 167,
+"y": 246
 },
 {
-"x": 250,
-"y": 268,
+"x": 167,
+"y": 355,
 "type": "cubic"
 },
 {
-"x": 259,
-"y": 283,
+"x": 203,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 274,
-"y": 283,
+"x": 257,
+"y": 402,
 "smooth": true
 },
 {
 "x": 285,
-"y": 283,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 294,
-"y": 280,
+"x": 315,
+"y": 390,
 "type": "cubic"
 },
 {
-"x": 300,
-"y": 276
+"x": 335,
+"y": 370
 },
 {
-"x": 300,
+"x": 335,
 "y": 0
 },
 {
-"x": 520,
+"x": 425,
 "y": 0
 },
 {
-"x": 520,
-"y": 448
+"x": 425,
+"y": 423
 },
 {
-"x": 480,
-"y": 478,
+"x": 395,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 420,
-"y": 501,
+"x": 350,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 347,
-"y": 501,
+"x": 274,
+"y": 490,
 "smooth": true
 },
 {
-"x": 259,
-"y": 501,
+"x": 205,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 209,
-"y": 461,
+"x": 170,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 188,
-"y": 401
+"x": 155,
+"y": 409
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 560,
+"xAdvance": 528,
 "anchors": [
 {
 "name": "_connect",
-"x": 250,
+"x": 167,
 "y": 0
 },
 {
 "name": "connect",
-"x": 520,
+"x": 425,
 "y": 0
 }
 ]
 }
 },
-"Light (layer #0)": {
+"65575EEB-523C-4A39-985D-FB9ACFE951AF": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 102,
-"y": 384
+"x": 131,
+"y": 379
 },
 {
-"x": 117,
-"y": 266
+"x": 167,
+"y": 216
 },
 {
-"x": 117,
-"y": 410,
+"x": 167,
+"y": 325,
 "type": "cubic"
 },
 {
-"x": 173,
-"y": 463,
+"x": 203,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 262,
-"y": 463,
+"x": 277,
+"y": 402,
 "smooth": true
 },
 {
-"x": 322,
-"y": 463,
+"x": 315,
+"y": 402,
 "type": "cubic"
 },
 {
-"x": 365,
-"y": 437,
+"x": 345,
+"y": 390,
 "type": "cubic"
 },
 {
-"x": 394,
-"y": 408
+"x": 365,
+"y": 370
 },
 {
-"x": 394,
+"x": 365,
 "y": 0
 },
 {
-"x": 411,
+"x": 455,
 "y": 0
 },
 {
-"x": 411,
-"y": 414
+"x": 455,
+"y": 423
 },
 {
-"x": 377,
-"y": 450,
+"x": 425,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 333,
-"y": 479,
+"x": 380,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 262,
-"y": 479,
+"x": 294,
+"y": 490,
 "smooth": true
 },
 {
-"x": 169,
-"y": 479,
+"x": 205,
+"y": 490,
 "type": "cubic"
 },
 {
-"x": 132,
-"y": 429,
+"x": 170,
+"y": 452,
 "type": "cubic"
 },
 {
-"x": 121,
-"y": 384
+"x": 155,
+"y": 379
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 501,
+"xAdvance": 528,
 "anchors": [
 {
 "name": "_connect",
-"x": 117,
+"x": 167,
 "y": 0
 },
 {
 "name": "connect",
-"x": 411,
+"x": 455,
 "y": 0
 }
 ]
 }
 },
-"Light / LowCrotch (layer #4)": {
+"7C8F98EE-D140-44D5-86AE-E00A730464C0": {
 "glyph": {
 "path": {
 "contours": [
@@ -606,417 +606,417 @@
 ]
 }
 },
-"Light / NarrowShoulder (layer #3)": {
+"BA4F7DF9-9552-48BB-A5B8-E2D21D8D086E": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 102,
-"y": 384
+"x": 162,
+"y": 371
 },
 {
-"x": 117,
-"y": 266
+"x": 250,
+"y": 199
 },
 {
-"x": 117,
-"y": 410,
+"x": 250,
+"y": 251,
 "type": "cubic"
 },
 {
-"x": 173,
-"y": 463,
+"x": 259,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 252,
-"y": 463,
+"x": 284,
+"y": 283,
 "smooth": true
 },
 {
-"x": 292,
-"y": 463,
+"x": 295,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 335,
-"y": 437,
+"x": 304,
+"y": 280,
 "type": "cubic"
 },
 {
-"x": 364,
-"y": 408
+"x": 310,
+"y": 276
 },
 {
-"x": 364,
+"x": 310,
 "y": 0
 },
 {
-"x": 381,
+"x": 530,
 "y": 0
 },
 {
-"x": 381,
-"y": 414
+"x": 530,
+"y": 448
 },
 {
-"x": 347,
-"y": 450,
+"x": 490,
+"y": 478,
 "type": "cubic"
 },
 {
-"x": 303,
-"y": 479,
+"x": 430,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 252,
-"y": 479,
+"x": 357,
+"y": 501,
 "smooth": true
 },
 {
-"x": 169,
-"y": 479,
+"x": 259,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 132,
-"y": 429,
+"x": 209,
+"y": 461,
 "type": "cubic"
 },
 {
-"x": 121,
-"y": 384
+"x": 188,
+"y": 371
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 501,
+"xAdvance": 560,
 "anchors": [
 {
 "name": "_connect",
-"x": 117,
+"x": 250,
 "y": 0
 },
 {
 "name": "connect",
-"x": 381,
+"x": 530,
 "y": 0
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 131,
-"y": 409
+"x": 162,
+"y": 401
 },
 {
-"x": 167,
-"y": 246
+"x": 250,
+"y": 229
 },
 {
-"x": 167,
-"y": 355,
+"x": 250,
+"y": 268,
 "type": "cubic"
 },
 {
-"x": 203,
-"y": 402,
+"x": 259,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 277,
-"y": 402,
+"x": 284,
+"y": 283,
 "smooth": true
 },
 {
-"x": 315,
-"y": 402,
+"x": 295,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 345,
-"y": 390,
+"x": 304,
+"y": 280,
 "type": "cubic"
 },
 {
-"x": 365,
-"y": 370
+"x": 310,
+"y": 276
 },
 {
-"x": 365,
+"x": 310,
 "y": 0
 },
 {
-"x": 455,
+"x": 530,
 "y": 0
 },
 {
-"x": 455,
-"y": 423
+"x": 530,
+"y": 448
 },
 {
-"x": 425,
-"y": 452,
+"x": 490,
+"y": 478,
 "type": "cubic"
 },
 {
-"x": 380,
-"y": 490,
+"x": 430,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 294,
-"y": 490,
+"x": 357,
+"y": 501,
 "smooth": true
 },
 {
-"x": 205,
-"y": 490,
+"x": 259,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 170,
-"y": 452,
+"x": 209,
+"y": 461,
 "type": "cubic"
 },
 {
-"x": 155,
-"y": 409
+"x": 188,
+"y": 401
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 528,
+"xAdvance": 560,
 "anchors": [
 {
 "name": "_connect",
-"x": 167,
+"x": 250,
 "y": 0
 },
 {
 "name": "connect",
-"x": 455,
+"x": 530,
 "y": 0
 }
 ]
 }
 },
-"Regular / LowCrotch (layer #6)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 131,
-"y": 379
+"x": 102,
+"y": 384
 },
 {
-"x": 167,
-"y": 216
+"x": 117,
+"y": 266
 },
 {
-"x": 167,
-"y": 325,
+"x": 117,
+"y": 410,
 "type": "cubic"
 },
 {
-"x": 203,
-"y": 402,
+"x": 173,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 277,
-"y": 402,
+"x": 262,
+"y": 463,
 "smooth": true
 },
 {
-"x": 315,
-"y": 402,
+"x": 322,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 345,
-"y": 390,
+"x": 365,
+"y": 437,
 "type": "cubic"
 },
 {
-"x": 365,
-"y": 370
+"x": 394,
+"y": 408
 },
 {
-"x": 365,
+"x": 394,
 "y": 0
 },
 {
-"x": 455,
+"x": 411,
 "y": 0
 },
 {
-"x": 455,
-"y": 423
+"x": 411,
+"y": 414
 },
 {
-"x": 425,
-"y": 452,
+"x": 377,
+"y": 450,
 "type": "cubic"
 },
 {
-"x": 380,
-"y": 490,
+"x": 333,
+"y": 479,
 "type": "cubic"
 },
 {
-"x": 294,
-"y": 490,
+"x": 262,
+"y": 479,
 "smooth": true
 },
 {
-"x": 205,
-"y": 490,
+"x": 169,
+"y": 479,
 "type": "cubic"
 },
 {
-"x": 170,
-"y": 452,
+"x": 132,
+"y": 429,
 "type": "cubic"
 },
 {
-"x": 155,
-"y": 379
+"x": 121,
+"y": 384
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 528,
+"xAdvance": 501,
 "anchors": [
 {
 "name": "_connect",
-"x": 167,
+"x": 117,
 "y": 0
 },
 {
 "name": "connect",
-"x": 455,
+"x": 411,
 "y": 0
 }
 ]
 }
 },
-"Regular / NarrowShoulder (layer #5)": {
+"D607B100-382C-478B-A297-2EF174C3A363": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 131,
-"y": 409
+"x": 162,
+"y": 401
 },
 {
-"x": 167,
-"y": 246
+"x": 250,
+"y": 229
 },
 {
-"x": 167,
-"y": 355,
+"x": 250,
+"y": 268,
 "type": "cubic"
 },
 {
-"x": 203,
-"y": 402,
+"x": 259,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 257,
-"y": 402,
+"x": 274,
+"y": 283,
 "smooth": true
 },
 {
 "x": 285,
-"y": 402,
+"y": 283,
 "type": "cubic"
 },
 {
-"x": 315,
-"y": 390,
+"x": 294,
+"y": 280,
 "type": "cubic"
 },
 {
-"x": 335,
-"y": 370
+"x": 300,
+"y": 276
 },
 {
-"x": 335,
+"x": 300,
 "y": 0
 },
 {
-"x": 425,
+"x": 520,
 "y": 0
 },
 {
-"x": 425,
-"y": 423
+"x": 520,
+"y": 448
 },
 {
-"x": 395,
-"y": 452,
+"x": 480,
+"y": 478,
 "type": "cubic"
 },
 {
-"x": 350,
-"y": 490,
+"x": 420,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 274,
-"y": 490,
+"x": 347,
+"y": 501,
 "smooth": true
 },
 {
-"x": 205,
-"y": 490,
+"x": 259,
+"y": 501,
 "type": "cubic"
 },
 {
-"x": 170,
-"y": 452,
+"x": 209,
+"y": 461,
 "type": "cubic"
 },
 {
-"x": 155,
-"y": 409
+"x": 188,
+"y": 401
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 528,
+"xAdvance": 560,
 "anchors": [
 {
 "name": "_connect",
-"x": 167,
+"x": 250,
 "y": 0
 },
 {
 "name": "connect",
-"x": 425,
+"x": 520,
 "y": 0
 }
 ]
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.stem.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.stem.json
index d167c72..09b740e 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.stem.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/_part.stem.json
@@ -11,14 +11,14 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Light / TallStem",
-"layerName": "Light / TallStem (layer #3)",
+"layerName": "0D68D3E9-A0B2-4D78-A161-EB65D8511F0A",
 "location": {
 "Weight": 17,
 "height": 100
@@ -26,14 +26,14 @@
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Regular / TallStem",
-"layerName": "Regular / TallStem (layer #4)",
+"layerName": "3E1733D9-3B83-4E6A-B1E9-6381BBE1BD3A",
 "location": {
 "Weight": 90,
 "height": 100
@@ -41,14 +41,14 @@
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 },
 {
 "name": "Bold / TallStem",
-"layerName": "Bold / TallStem (layer #5)",
+"layerName": "FD65D427-9013-43E2-9F74-398D99AA4763",
 "location": {
 "Weight": 220,
 "height": 100
@@ -56,34 +56,34 @@
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"0D68D3E9-A0B2-4D78-A161-EB65D8511F0A": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 250,
-"y": 256
+"x": 117,
+"y": 306
 },
 {
-"x": 181,
-"y": 385
+"x": 117,
+"y": 368
 },
 {
-"x": 162,
-"y": 490
+"x": 117,
+"y": 800
 },
 {
-"x": 30,
-"y": 490
+"x": 100,
+"y": 800
 },
 {
-"x": 30,
+"x": 100,
 "y": 0
 },
 {
-"x": 250,
+"x": 117,
 "y": 0
 }
 ],
@@ -95,40 +95,40 @@
 "anchors": [
 {
 "name": "connect",
-"x": 250,
+"x": 117,
 "y": 0
 }
 ]
 }
 },
-"Bold / TallStem (layer #5)": {
+"3E1733D9-3B83-4E6A-B1E9-6381BBE1BD3A": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 250,
-"y": 256
+"x": 167,
+"y": 286
 },
 {
-"x": 250,
-"y": 385
+"x": 167,
+"y": 393
 },
 {
-"x": 250,
+"x": 167,
 "y": 800
 },
 {
-"x": 30,
+"x": 77,
 "y": 800
 },
 {
-"x": 30,
+"x": 77,
 "y": 0
 },
 {
-"x": 250,
+"x": 167,
 "y": 0
 }
 ],
@@ -140,40 +140,40 @@
 "anchors": [
 {
 "name": "connect",
-"x": 250,
+"x": 167,
 "y": 0
 }
 ]
 }
 },
-"Light (layer #0)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 117,
-"y": 306
+"x": 167,
+"y": 286
 },
 {
-"x": 119,
-"y": 368
+"x": 149,
+"y": 393
 },
 {
-"x": 115,
-"y": 470
+"x": 139,
+"y": 480
 },
 {
-"x": 100,
-"y": 470
+"x": 77,
+"y": 480
 },
 {
-"x": 100,
+"x": 77,
 "y": 0
 },
 {
-"x": 117,
+"x": 167,
 "y": 0
 }
 ],
@@ -185,40 +185,40 @@
 "anchors": [
 {
 "name": "connect",
-"x": 117,
+"x": 167,
 "y": 0
 }
 ]
 }
 },
-"Light / TallStem (layer #3)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 117,
-"y": 306
+"x": 250,
+"y": 256
 },
 {
-"x": 117,
-"y": 368
+"x": 181,
+"y": 385
 },
 {
-"x": 117,
-"y": 800
+"x": 162,
+"y": 490
 },
 {
-"x": 100,
-"y": 800
+"x": 30,
+"y": 490
 },
 {
-"x": 100,
+"x": 30,
 "y": 0
 },
 {
-"x": 117,
+"x": 250,
 "y": 0
 }
 ],
@@ -230,40 +230,40 @@
 "anchors": [
 {
 "name": "connect",
-"x": 117,
+"x": 250,
 "y": 0
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 167,
-"y": 286
+"x": 117,
+"y": 306
 },
 {
-"x": 149,
-"y": 393
+"x": 119,
+"y": 368
 },
 {
-"x": 139,
-"y": 480
+"x": 115,
+"y": 470
 },
 {
-"x": 77,
-"y": 480
+"x": 100,
+"y": 470
 },
 {
-"x": 77,
+"x": 100,
 "y": 0
 },
 {
-"x": 167,
+"x": 117,
 "y": 0
 }
 ],
@@ -275,40 +275,40 @@
 "anchors": [
 {
 "name": "connect",
-"x": 167,
+"x": 117,
 "y": 0
 }
 ]
 }
 },
-"Regular / TallStem (layer #4)": {
+"FD65D427-9013-43E2-9F74-398D99AA4763": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 167,
-"y": 286
+"x": 250,
+"y": 256
 },
 {
-"x": 167,
-"y": 393
+"x": 250,
+"y": 385
 },
 {
-"x": 167,
+"x": 250,
 "y": 800
 },
 {
-"x": 77,
+"x": 30,
 "y": 800
 },
 {
-"x": 77,
+"x": 30,
 "y": 0
 },
 {
-"x": 167,
+"x": 250,
 "y": 0
 }
 ],
@@ -320,7 +320,7 @@
 "anchors": [
 {
 "name": "connect",
-"x": 167,
+"x": 250,
 "y": 0
 }
 ]
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.json
index e93d988..cce9993 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.json
@@ -3,498 +3,495 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Regular / {155, 100}",
-"layerName": "Regular / {155, 100} (layer #3)",
+"layerName": "1FA54028-AD2E-4209-AA7B-72DF2DF16264",
 "location": {
 "Weight": 155
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"1FA54028-AD2E-4209-AA7B-72DF2DF16264": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 268,
-"y": 392
+"x": 301,
+"y": 423
 },
 {
-"x": 268,
-"y": 153,
+"x": 301,
+"y": 174,
 "smooth": true
 },
 {
-"x": 268,
-"y": 123,
+"x": 301,
+"y": 129,
 "type": "cubic"
 },
 {
-"x": 254,
-"y": 113,
+"x": 272,
+"y": 107,
 "type": "cubic"
 },
 {
-"x": 236,
-"y": 113,
+"x": 224,
+"y": 107,
 "smooth": true
 },
 {
-"x": 214,
-"y": 113,
+"x": 182,
+"y": 107,
 "type": "cubic"
 },
 {
-"x": 205,
-"y": 127,
+"x": 169,
+"y": 123,
 "type": "cubic"
 },
 {
-"x": 205,
-"y": 143,
+"x": 169,
+"y": 140,
 "smooth": true
 },
 {
-"x": 205,
+"x": 169,
 "y": 155,
 "type": "cubic"
 },
 {
-"x": 210,
-"y": 164,
+"x": 178,
+"y": 165,
 "type": "cubic"
 },
 {
-"x": 218,
-"y": 170,
+"x": 191,
+"y": 172,
 "smooth": true
 },
 {
-"x": 233,
-"y": 181,
+"x": 216,
+"y": 185,
 "type": "cubic"
 },
 {
-"x": 254,
-"y": 182,
+"x": 259,
+"y": 186,
 "type": "cubic"
 },
 {
-"x": 275,
-"y": 182
+"x": 307,
+"y": 186
 },
 {
-"x": 295,
-"y": 289
+"x": 306,
+"y": 298
 },
 {
-"x": 203,
-"y": 289,
+"x": 216,
+"y": 294,
 "type": "cubic"
 },
 {
-"x": 123,
-"y": 277,
+"x": 148,
+"y": 288,
 "type": "cubic"
 },
 {
-"x": 72,
-"y": 240,
+"x": 97,
+"y": 255,
 "smooth": true
 },
 {
-"x": 40,
-"y": 216,
+"x": 58,
+"y": 230,
 "type": "cubic"
 },
 {
-"x": 21,
-"y": 182,
+"x": 34,
+"y": 190,
 "type": "cubic"
 },
 {
-"x": 21,
-"y": 133,
+"x": 34,
+"y": 132,
 "smooth": true
 },
 {
-"x": 21,
-"y": 49,
+"x": 34,
+"y": 47,
 "type": "cubic"
 },
 {
-"x": 75,
-"y": -8,
+"x": 81,
+"y": -10,
 "type": "cubic"
 },
 {
-"x": 184,
-"y": -8,
+"x": 190,
+"y": -10,
 "smooth": true
 },
 {
-"x": 250,
-"y": -8,
+"x": 252,
+"y": -10,
 "type": "cubic"
 },
 {
-"x": 288,
-"y": 12,
+"x": 297,
+"y": 8,
 "type": "cubic"
 },
 {
-"x": 310,
-"y": 44
+"x": 320,
+"y": 42
 },
 {
-"x": 320,
-"y": 44
+"x": 329,
+"y": 42
 },
 {
-"x": 336,
+"x": 341,
 "y": 0
 },
 {
-"x": 488,
+"x": 446,
 "y": 0
 },
 {
-"x": 488,
-"y": 454
+"x": 446,
+"y": 445
 },
 {
-"x": 437,
-"y": 484,
+"x": 400,
+"y": 476,
 "type": "cubic"
 },
 {
-"x": 354,
-"y": 505,
+"x": 326,
+"y": 499,
 "type": "cubic"
 },
 {
-"x": 255,
-"y": 505,
+"x": 236,
+"y": 499,
 "smooth": true
 },
 {
-"x": 167,
-"y": 505,
+"x": 160,
+"y": 499,
 "type": "cubic"
 },
 {
-"x": 86,
-"y": 489,
+"x": 92,
+"y": 483,
 "type": "cubic"
 },
 {
-"x": 25,
+"x": 39,
 "y": 461
 },
 {
-"x": 56,
-"y": 298
+"x": 61,
+"y": 329
 },
 {
-"x": 90,
-"y": 311,
+"x": 96,
+"y": 343,
 "type": "cubic"
 },
 {
-"x": 134,
-"y": 322,
+"x": 141,
+"y": 355,
 "type": "cubic"
 },
 {
-"x": 194,
-"y": 322,
+"x": 200,
+"y": 355,
 "smooth": true
 },
 {
-"x": 225,
-"y": 322,
+"x": 234,
+"y": 355,
 "type": "cubic"
 },
 {
-"x": 270,
-"y": 319,
+"x": 281,
+"y": 351,
 "type": "cubic"
 },
 {
-"x": 308,
-"y": 305
+"x": 321,
+"y": 327
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 518,
+"xAdvance": 496,
 "anchors": [
 {
 "name": "bottom",
-"x": 184,
+"x": 189,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 488,
+"x": 446,
 "y": 0
 },
 {
 "name": "top",
-"x": 258,
-"y": 490
+"x": 237,
+"y": 485
 }
 ]
 }
 },
-"Light (layer #0)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 352,
-"y": 429
+"x": 333,
+"y": 454
 },
 {
-"x": 352,
-"y": 147,
-"smooth": true,
-"attrs": {
-"name": "Hello"
-}
+"x": 333,
+"y": 176,
+"smooth": true
 },
 {
-"x": 352,
-"y": 68,
+"x": 333,
+"y": 119,
 "type": "cubic"
 },
 {
-"x": 314,
-"y": 7,
+"x": 309,
+"y": 69,
 "type": "cubic"
 },
 {
-"x": 212,
-"y": 7,
+"x": 231,
+"y": 69,
 "smooth": true
 },
 {
-"x": 132,
-"y": 7,
+"x": 170,
+"y": 69,
 "type": "cubic"
 },
 {
-"x": 97,
-"y": 47,
+"x": 153,
+"y": 99,
 "type": "cubic"
 },
 {
-"x": 97,
-"y": 105,
+"x": 153,
+"y": 127,
 "smooth": true
 },
 {
-"x": 97,
-"y": 136,
+"x": 153,
+"y": 152,
 "type": "cubic"
 },
 {
-"x": 107,
-"y": 160,
+"x": 166,
+"y": 169,
 "type": "cubic"
 },
 {
-"x": 125,
-"y": 178,
+"x": 183,
+"y": 179,
 "smooth": true
 },
 {
-"x": 166,
-"y": 219,
+"x": 219,
+"y": 200,
 "type": "cubic"
 },
 {
-"x": 249,
-"y": 224,
+"x": 284,
+"y": 204,
 "type": "cubic"
 },
 {
-"x": 355,
-"y": 224
+"x": 338,
+"y": 204
 },
 {
-"x": 355,
-"y": 241
+"x": 338,
+"y": 282
 },
 {
-"x": 245,
-"y": 241,
+"x": 249,
+"y": 282,
 "type": "cubic"
 },
 {
-"x": 158,
-"y": 233,
+"x": 193,
+"y": 276,
 "type": "cubic"
 },
 {
-"x": 113,
-"y": 190,
+"x": 142,
+"y": 251,
 "smooth": true
 },
 {
-"x": 92,
-"y": 169,
+"x": 94,
+"y": 227,
 "type": "cubic"
 },
 {
-"x": 80,
-"y": 141,
+"x": 65,
+"y": 185,
 "type": "cubic"
 },
 {
-"x": 80,
-"y": 105,
+"x": 65,
+"y": 125,
 "smooth": true
 },
 {
-"x": 80,
-"y": 39,
+"x": 65,
+"y": 42,
 "type": "cubic"
 },
 {
 "x": 119,
-"y": -10,
+"y": -11,
 "type": "cubic"
 },
 {
-"x": 212,
-"y": -10,
+"x": 215,
+"y": -11,
 "smooth": true
 },
 {
-"x": 283,
-"y": -10,
+"x": 277,
+"y": -11,
 "type": "cubic"
 },
 {
-"x": 334,
-"y": 18,
+"x": 310,
+"y": 11,
 "type": "cubic"
 },
 {
-"x": 349,
-"y": 68
+"x": 330,
+"y": 41
 },
 {
-"x": 352,
-"y": 68
+"x": 338,
+"y": 41
 },
 {
-"x": 354,
+"x": 346,
 "y": 0
 },
 {
-"x": 369,
+"x": 423,
 "y": 0
 },
 {
-"x": 369,
-"y": 428
+"x": 423,
+"y": 435
 },
 {
-"x": 333,
-"y": 460,
+"x": 383,
+"y": 468,
 "type": "cubic"
 },
 {
-"x": 291,
-"y": 480,
+"x": 316,
+"y": 492,
 "type": "cubic"
 },
 {
-"x": 224,
-"y": 480,
+"x": 232,
+"y": 492,
 "smooth": true
 },
 {
-"x": 163,
-"y": 480,
+"x": 171,
+"y": 492,
 "type": "cubic"
 },
 {
 "x": 116,
-"y": 462,
+"y": 479,
 "type": "cubic"
 },
 {
-"x": 82,
-"y": 438
+"x": 72,
+"y": 460
 },
 {
-"x": 87,
-"y": 423
+"x": 86,
+"y": 371
 },
 {
-"x": 123,
-"y": 448,
+"x": 122,
+"y": 388,
 "type": "cubic"
 },
 {
-"x": 167,
-"y": 463,
+"x": 166,
+"y": 400,
 "type": "cubic"
 },
 {
-"x": 224,
-"y": 463,
+"x": 225,
+"y": 400,
 "smooth": true
 },
 {
-"x": 284,
-"y": 463,
+"x": 262,
+"y": 400,
 "type": "cubic"
 },
 {
-"x": 323,
-"y": 445,
+"x": 312,
+"y": 395,
 "type": "cubic"
 },
 {
-"x": 355,
-"y": 417
+"x": 353,
+"y": 361
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 456,
+"xAdvance": 496,
 "anchors": [
 {
 "name": "bottom",
@@ -503,493 +500,496 @@
 },
 {
 "name": "ogonek",
-"x": 369,
+"x": 423,
 "y": 0
 },
 {
 "name": "top",
-"x": 226,
-"y": 471
+"x": 248,
+"y": 480
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 333,
-"y": 454
+"x": 268,
+"y": 392
 },
 {
-"x": 333,
-"y": 176,
+"x": 268,
+"y": 153,
 "smooth": true
 },
 {
-"x": 333,
-"y": 119,
+"x": 268,
+"y": 123,
 "type": "cubic"
 },
 {
-"x": 309,
-"y": 69,
+"x": 254,
+"y": 113,
 "type": "cubic"
 },
 {
-"x": 231,
-"y": 69,
+"x": 236,
+"y": 113,
 "smooth": true
 },
 {
-"x": 170,
-"y": 69,
+"x": 214,
+"y": 113,
 "type": "cubic"
 },
 {
-"x": 153,
-"y": 99,
+"x": 205,
+"y": 127,
 "type": "cubic"
 },
 {
-"x": 153,
-"y": 127,
+"x": 205,
+"y": 143,
 "smooth": true
 },
 {
-"x": 153,
-"y": 152,
+"x": 205,
+"y": 155,
 "type": "cubic"
 },
 {
-"x": 166,
-"y": 169,
+"x": 210,
+"y": 164,
 "type": "cubic"
 },
 {
-"x": 183,
-"y": 179,
+"x": 218,
+"y": 170,
 "smooth": true
 },
 {
-"x": 219,
-"y": 200,
+"x": 233,
+"y": 181,
 "type": "cubic"
 },
 {
-"x": 284,
-"y": 204,
+"x": 254,
+"y": 182,
 "type": "cubic"
 },
 {
-"x": 338,
-"y": 204
+"x": 275,
+"y": 182
 },
 {
-"x": 338,
-"y": 282
+"x": 295,
+"y": 289
 },
 {
-"x": 249,
-"y": 282,
+"x": 203,
+"y": 289,
 "type": "cubic"
 },
 {
-"x": 193,
-"y": 276,
+"x": 123,
+"y": 277,
 "type": "cubic"
 },
 {
-"x": 142,
-"y": 251,
+"x": 72,
+"y": 240,
 "smooth": true
 },
 {
-"x": 94,
-"y": 227,
+"x": 40,
+"y": 216,
 "type": "cubic"
 },
 {
-"x": 65,
-"y": 185,
+"x": 21,
+"y": 182,
 "type": "cubic"
 },
 {
-"x": 65,
-"y": 125,
+"x": 21,
+"y": 133,
 "smooth": true
 },
 {
-"x": 65,
-"y": 42,
+"x": 21,
+"y": 49,
 "type": "cubic"
 },
 {
-"x": 119,
-"y": -11,
+"x": 75,
+"y": -8,
 "type": "cubic"
 },
 {
-"x": 215,
-"y": -11,
+"x": 184,
+"y": -8,
 "smooth": true
 },
 {
-"x": 277,
-"y": -11,
+"x": 250,
+"y": -8,
 "type": "cubic"
 },
 {
-"x": 310,
-"y": 11,
+"x": 288,
+"y": 12,
 "type": "cubic"
 },
 {
-"x": 330,
-"y": 41
+"x": 310,
+"y": 44
 },
 {
-"x": 338,
-"y": 41
+"x": 320,
+"y": 44
 },
 {
-"x": 346,
+"x": 336,
 "y": 0
 },
 {
-"x": 423,
+"x": 488,
 "y": 0
 },
 {
-"x": 423,
-"y": 435
+"x": 488,
+"y": 454
 },
 {
-"x": 383,
-"y": 468,
+"x": 437,
+"y": 484,
 "type": "cubic"
 },
 {
-"x": 316,
-"y": 492,
+"x": 354,
+"y": 505,
 "type": "cubic"
 },
 {
-"x": 232,
-"y": 492,
+"x": 255,
+"y": 505,
 "smooth": true
 },
 {
-"x": 171,
-"y": 492,
+"x": 167,
+"y": 505,
 "type": "cubic"
 },
 {
-"x": 116,
-"y": 479,
+"x": 86,
+"y": 489,
 "type": "cubic"
 },
 {
-"x": 72,
-"y": 460
+"x": 25,
+"y": 461
 },
 {
-"x": 86,
-"y": 371
+"x": 56,
+"y": 298
 },
 {
-"x": 122,
-"y": 388,
+"x": 90,
+"y": 311,
 "type": "cubic"
 },
 {
-"x": 166,
-"y": 400,
+"x": 134,
+"y": 322,
 "type": "cubic"
 },
 {
-"x": 225,
-"y": 400,
+"x": 194,
+"y": 322,
 "smooth": true
 },
 {
-"x": 262,
-"y": 400,
+"x": 225,
+"y": 322,
 "type": "cubic"
 },
 {
-"x": 312,
-"y": 395,
+"x": 270,
+"y": 319,
 "type": "cubic"
 },
 {
-"x": 353,
-"y": 361
+"x": 308,
+"y": 305
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 496,
+"xAdvance": 518,
 "anchors": [
 {
 "name": "bottom",
-"x": 218,
+"x": 184,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 423,
+"x": 488,
 "y": 0
 },
 {
 "name": "top",
-"x": 248,
-"y": 480
+"x": 258,
+"y": 490
 }
 ]
 }
 },
-"Regular / {155, 100} (layer #3)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 301,
-"y": 423
+"x": 352,
+"y": 429
 },
 {
-"x": 301,
-"y": 174,
-"smooth": true
+"x": 352,
+"y": 147,
+"smooth": true,
+"attrs": {
+"name": "Hello"
+}
 },
 {
-"x": 301,
-"y": 129,
+"x": 352,
+"y": 68,
 "type": "cubic"
 },
 {
-"x": 272,
-"y": 107,
+"x": 314,
+"y": 7,
 "type": "cubic"
 },
 {
-"x": 224,
-"y": 107,
+"x": 212,
+"y": 7,
 "smooth": true
 },
 {
-"x": 182,
-"y": 107,
+"x": 132,
+"y": 7,
 "type": "cubic"
 },
 {
-"x": 169,
-"y": 123,
+"x": 97,
+"y": 47,
 "type": "cubic"
 },
 {
-"x": 169,
-"y": 140,
+"x": 97,
+"y": 105,
 "smooth": true
 },
 {
-"x": 169,
-"y": 155,
+"x": 97,
+"y": 136,
 "type": "cubic"
 },
 {
-"x": 178,
-"y": 165,
+"x": 107,
+"y": 160,
 "type": "cubic"
 },
 {
-"x": 191,
-"y": 172,
+"x": 125,
+"y": 178,
 "smooth": true
 },
 {
-"x": 216,
-"y": 185,
+"x": 166,
+"y": 219,
 "type": "cubic"
 },
 {
-"x": 259,
-"y": 186,
+"x": 249,
+"y": 224,
 "type": "cubic"
 },
 {
-"x": 307,
-"y": 186
+"x": 355,
+"y": 224
 },
 {
-"x": 306,
-"y": 298
+"x": 355,
+"y": 241
 },
 {
-"x": 216,
-"y": 294,
+"x": 245,
+"y": 241,
 "type": "cubic"
 },
 {
-"x": 148,
-"y": 288,
+"x": 158,
+"y": 233,
 "type": "cubic"
 },
 {
-"x": 97,
-"y": 255,
+"x": 113,
+"y": 190,
 "smooth": true
 },
 {
-"x": 58,
-"y": 230,
+"x": 92,
+"y": 169,
 "type": "cubic"
 },
 {
-"x": 34,
-"y": 190,
+"x": 80,
+"y": 141,
 "type": "cubic"
 },
 {
-"x": 34,
-"y": 132,
+"x": 80,
+"y": 105,
 "smooth": true
 },
 {
-"x": 34,
-"y": 47,
+"x": 80,
+"y": 39,
 "type": "cubic"
 },
 {
-"x": 81,
+"x": 119,
 "y": -10,
 "type": "cubic"
 },
 {
-"x": 190,
+"x": 212,
 "y": -10,
 "smooth": true
 },
 {
-"x": 252,
+"x": 283,
 "y": -10,
 "type": "cubic"
 },
 {
-"x": 297,
-"y": 8,
+"x": 334,
+"y": 18,
 "type": "cubic"
 },
 {
-"x": 320,
-"y": 42
+"x": 349,
+"y": 68
 },
 {
-"x": 329,
-"y": 42
+"x": 352,
+"y": 68
 },
 {
-"x": 341,
+"x": 354,
 "y": 0
 },
 {
-"x": 446,
+"x": 369,
 "y": 0
 },
 {
-"x": 446,
-"y": 445
+"x": 369,
+"y": 428
 },
 {
-"x": 400,
-"y": 476,
+"x": 333,
+"y": 460,
 "type": "cubic"
 },
 {
-"x": 326,
-"y": 499,
+"x": 291,
+"y": 480,
 "type": "cubic"
 },
 {
-"x": 236,
-"y": 499,
+"x": 224,
+"y": 480,
 "smooth": true
 },
 {
-"x": 160,
-"y": 499,
+"x": 163,
+"y": 480,
 "type": "cubic"
 },
 {
-"x": 92,
-"y": 483,
+"x": 116,
+"y": 462,
 "type": "cubic"
 },
 {
-"x": 39,
-"y": 461
+"x": 82,
+"y": 438
 },
 {
-"x": 61,
-"y": 329
+"x": 87,
+"y": 423
 },
 {
-"x": 96,
-"y": 343,
+"x": 123,
+"y": 448,
 "type": "cubic"
 },
 {
-"x": 141,
-"y": 355,
+"x": 167,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 200,
-"y": 355,
+"x": 224,
+"y": 463,
 "smooth": true
 },
 {
-"x": 234,
-"y": 355,
+"x": 284,
+"y": 463,
 "type": "cubic"
 },
 {
-"x": 281,
-"y": 351,
+"x": 323,
+"y": 445,
 "type": "cubic"
 },
 {
-"x": 321,
-"y": 327
+"x": 355,
+"y": 417
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 496,
+"xAdvance": 456,
 "anchors": [
 {
 "name": "bottom",
-"x": 189,
+"x": 218,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 446,
+"x": 369,
 "y": 0
 },
 {
 "name": "top",
-"x": 237,
-"y": 485
+"x": 226,
+"y": 471
 }
 ]
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.sc.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.sc.json
index 4c76f93..3dd18fd 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.sc.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/a.sc.json
@@ -3,63 +3,63 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 608,
+"x": 511,
 "y": 0
 },
 {
-"x": 461,
-"y": 552
+"x": 357,
+"y": 540
 },
 {
-"x": 158,
-"y": 552
+"x": 191,
+"y": 540
 },
 {
-"x": 5,
+"x": 24,
 "y": 0
 },
 {
-"x": 208,
+"x": 119,
 "y": 0
 },
 {
-"x": 289,
-"y": 351
+"x": 255,
+"y": 448
 },
 {
-"x": 312,
-"y": 351
+"x": 277,
+"y": 448
 },
 {
-"x": 395,
+"x": 414,
 "y": 0
 }
 ],
@@ -68,82 +68,82 @@
 {
 "points": [
 {
-"x": 498,
-"y": 234
+"x": 427,
+"y": 208
 },
 {
-"x": 122,
-"y": 234
+"x": 114,
+"y": 208
 },
 {
-"x": 115,
-"y": 65
+"x": 111,
+"y": 125
 },
 {
-"x": 495,
-"y": 65
+"x": 424,
+"y": 125
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 613,
+"xAdvance": 535,
 "anchors": [
 {
 "name": "bottom",
-"x": 307,
+"x": 268,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 608,
+"x": 511,
 "y": 0
 },
 {
 "name": "top",
-"x": 307,
-"y": 552
+"x": 268,
+"y": 540
 }
 ]
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 445,
+"x": 608,
 "y": 0
 },
 {
-"x": 252,
-"y": 528
+"x": 461,
+"y": 552
 },
 {
-"x": 228,
-"y": 528
+"x": 158,
+"y": 552
 },
 {
-"x": 33,
+"x": 5,
 "y": 0
 },
 {
-"x": 41,
+"x": 208,
 "y": 0
 },
 {
-"x": 234,
-"y": 519
+"x": 289,
+"y": 351
 },
 {
-"x": 247,
-"y": 519
+"x": 312,
+"y": 351
 },
 {
-"x": 437,
+"x": 395,
 "y": 0
 }
 ],
@@ -152,82 +152,82 @@
 {
 "points": [
 {
-"x": 380,
-"y": 167
+"x": 498,
+"y": 234
 },
 {
-"x": 99,
-"y": 167
+"x": 122,
+"y": 234
 },
 {
-"x": 95,
-"y": 159
+"x": 115,
+"y": 65
 },
 {
-"x": 384,
-"y": 159
+"x": 495,
+"y": 65
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 478,
+"xAdvance": 613,
 "anchors": [
 {
 "name": "bottom",
-"x": 240,
+"x": 307,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 445,
+"x": 608,
 "y": 0
 },
 {
 "name": "top",
-"x": 240,
-"y": 528
+"x": 307,
+"y": 552
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 511,
+"x": 445,
 "y": 0
 },
 {
-"x": 357,
-"y": 540
+"x": 252,
+"y": 528
 },
 {
-"x": 191,
-"y": 540
+"x": 228,
+"y": 528
 },
 {
-"x": 24,
+"x": 33,
 "y": 0
 },
 {
-"x": 119,
+"x": 41,
 "y": 0
 },
 {
-"x": 255,
-"y": 448
+"x": 234,
+"y": 519
 },
 {
-"x": 277,
-"y": 448
+"x": 247,
+"y": 519
 },
 {
-"x": 414,
+"x": 437,
 "y": 0
 }
 ],
@@ -236,42 +236,42 @@
 {
 "points": [
 {
-"x": 427,
-"y": 208
+"x": 380,
+"y": 167
 },
 {
-"x": 114,
-"y": 208
+"x": 99,
+"y": 167
 },
 {
-"x": 111,
-"y": 125
+"x": 95,
+"y": 159
 },
 {
-"x": 424,
-"y": 125
+"x": 384,
+"y": 159
 }
 ],
 "isClosed": true
 }
 ]
 },
-"xAdvance": 535,
+"xAdvance": 478,
 "anchors": [
 {
 "name": "bottom",
-"x": 268,
+"x": 240,
 "y": 0
 },
 {
 "name": "ogonek",
-"x": 511,
+"x": 445,
 "y": 0
 },
 {
 "name": "top",
-"x": 268,
-"y": 540
+"x": 240,
+"y": 528
 }
 ]
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/adieresis.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/adieresis.json
index ec17c59..e61514e 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/adieresis.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/adieresis.json
@@ -3,28 +3,28 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "components": [
 {
@@ -33,14 +33,14 @@
 {
 "name": "dieresis",
 "transformation": {
-"translateX": -9
+"translateX": 47
 }
 }
 ],
-"xAdvance": 518
+"xAdvance": 496
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "components": [
 {
@@ -49,15 +49,14 @@
 {
 "name": "dieresis",
 "transformation": {
-"translateX": 39,
-"translateY": 1
+"translateX": -9
 }
 }
 ],
-"xAdvance": 456
+"xAdvance": 518
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "components": [
 {
@@ -66,11 +65,12 @@
 {
 "name": "dieresis",
 "transformation": {
-"translateX": 47
+"translateX": 39,
+"translateY": 1
 }
 }
 ],
-"xAdvance": 496
+"xAdvance": 456
 }
 }
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/dieresis.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/dieresis.json
index 50d7882..ab0115b 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/dieresis.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/dieresis.json
@@ -3,48 +3,48 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 482,
-"y": 735
+"x": 349,
+"y": 700
 },
 {
-"x": 298,
-"y": 735
+"x": 252,
+"y": 700
 },
 {
-"x": 298,
-"y": 547
+"x": 252,
+"y": 601
 },
 {
-"x": 482,
-"y": 547
+"x": 349,
+"y": 601
 }
 ],
 "isClosed": true
@@ -52,20 +52,20 @@
 {
 "points": [
 {
-"x": 232,
-"y": 735
+"x": 149,
+"y": 700
 },
 {
-"x": 48,
-"y": 735
+"x": 52,
+"y": 700
 },
 {
-"x": 48,
-"y": 547
+"x": 52,
+"y": 601
 },
 {
-"x": 232,
-"y": 547
+"x": 149,
+"y": 601
 }
 ],
 "isClosed": true
@@ -76,38 +76,38 @@
 "anchors": [
 {
 "name": "_top",
-"x": 267,
-"y": 490
+"x": 201,
+"y": 480
 },
 {
 "name": "top",
-"x": 267,
-"y": 740
+"x": 201,
+"y": 700
 }
 ]
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 289,
-"y": 650
+"x": 482,
+"y": 735
 },
 {
-"x": 261,
-"y": 650
+"x": 298,
+"y": 735
 },
 {
-"x": 261,
-"y": 621
+"x": 298,
+"y": 547
 },
 {
-"x": 289,
-"y": 621
+"x": 482,
+"y": 547
 }
 ],
 "isClosed": true
@@ -115,20 +115,20 @@
 {
 "points": [
 {
-"x": 116,
-"y": 650
+"x": 232,
+"y": 735
 },
 {
-"x": 88,
-"y": 650
+"x": 48,
+"y": 735
 },
 {
-"x": 88,
-"y": 621
+"x": 48,
+"y": 547
 },
 {
-"x": 116,
-"y": 621
+"x": 232,
+"y": 547
 }
 ],
 "isClosed": true
@@ -139,38 +139,38 @@
 "anchors": [
 {
 "name": "_top",
-"x": 187,
-"y": 470
+"x": 267,
+"y": 490
 },
 {
 "name": "top",
-"x": 188,
-"y": 650
+"x": 267,
+"y": 740
 }
 ]
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "path": {
 "contours": [
 {
 "points": [
 {
-"x": 349,
-"y": 700
+"x": 289,
+"y": 650
 },
 {
-"x": 252,
-"y": 700
+"x": 261,
+"y": 650
 },
 {
-"x": 252,
-"y": 601
+"x": 261,
+"y": 621
 },
 {
-"x": 349,
-"y": 601
+"x": 289,
+"y": 621
 }
 ],
 "isClosed": true
@@ -178,20 +178,20 @@
 {
 "points": [
 {
-"x": 149,
-"y": 700
+"x": 116,
+"y": 650
 },
 {
-"x": 52,
-"y": 700
+"x": 88,
+"y": 650
 },
 {
-"x": 52,
-"y": 601
+"x": 88,
+"y": 621
 },
 {
-"x": 149,
-"y": 601
+"x": 116,
+"y": 621
 }
 ],
 "isClosed": true
@@ -202,13 +202,13 @@
 "anchors": [
 {
 "name": "_top",
-"x": 201,
-"y": 480
+"x": 187,
+"y": 470
 },
 {
 "name": "top",
-"x": 201,
-"y": 700
+"x": 188,
+"y": 650
 }
 ]
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/h.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/h.json
index 9fceaf0..e8925e4 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/h.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/h.json
@@ -3,28 +3,28 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "components": [
 {
@@ -40,10 +40,10 @@
 }
 }
 ],
-"xAdvance": 560
+"xAdvance": 532
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "components": [
 {
@@ -59,10 +59,10 @@
 }
 }
 ],
-"xAdvance": 511
+"xAdvance": 560
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "components": [
 {
@@ -78,7 +78,7 @@
 }
 }
 ],
-"xAdvance": 532
+"xAdvance": 511
 }
 }
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/m.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/m.json
index d19ee80..3cca04a 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/m.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/m.json
@@ -3,28 +3,28 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "components": [
 {
@@ -39,17 +39,17 @@
 {
 "name": "_part.shoulder",
 "transformation": {
-"translateX": 270
+"translateX": 258
 },
 "location": {
 "shoulderWidth": 0
 }
 }
 ],
-"xAdvance": 820
+"xAdvance": 760
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "components": [
 {
@@ -64,17 +64,17 @@
 {
 "name": "_part.shoulder",
 "transformation": {
-"translateX": 264
+"translateX": 270
 },
 "location": {
 "shoulderWidth": 0
 }
 }
 ],
-"xAdvance": 745
+"xAdvance": 820
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "components": [
 {
@@ -89,14 +89,14 @@
 {
 "name": "_part.shoulder",
 "transformation": {
-"translateX": 258
+"translateX": 264
 },
 "location": {
 "shoulderWidth": 0
 }
 }
 ],
-"xAdvance": 760
+"xAdvance": 745
 }
 }
 }
diff --git a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/n.json b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/n.json
index 2610e3d..68b738e 100644
--- a/tests/data/GlyphsUnitTestSans3.fontra/glyphs/n.json
+++ b/tests/data/GlyphsUnitTestSans3.fontra/glyphs/n.json
@@ -3,28 +3,28 @@
 "sources": [
 {
 "name": "Light",
-"layerName": "Light (layer #0)",
+"layerName": "C4872ECA-A3A9-40AB-960A-1DB2202F16DE",
 "location": {
 "Weight": 17
 }
 },
 {
 "name": "Regular",
-"layerName": "Regular (layer #1)",
+"layerName": "3E7589AA-8194-470F-8E2F-13C1C581BE24",
 "location": {
 "Weight": 90
 }
 },
 {
 "name": "Bold",
-"layerName": "Bold (layer #2)",
+"layerName": "BFFFD157-90D3-4B85-B99D-9A2F366F03CA",
 "location": {
 "Weight": 220
 }
 }
 ],
 "layers": {
-"Bold (layer #2)": {
+"3E7589AA-8194-470F-8E2F-13C1C581BE24": {
 "glyph": {
 "components": [
 {
@@ -34,10 +34,10 @@
 "name": "_part.stem"
 }
 ],
-"xAdvance": 560
+"xAdvance": 528
 }
 },
-"Light (layer #0)": {
+"BFFFD157-90D3-4B85-B99D-9A2F366F03CA": {
 "glyph": {
 "components": [
 {
@@ -47,10 +47,10 @@
 "name": "_part.stem"
 }
 ],
-"xAdvance": 501
+"xAdvance": 560
 }
 },
-"Regular (layer #1)": {
+"C4872ECA-A3A9-40AB-960A-1DB2202F16DE": {
 "glyph": {
 "components": [
 {
@@ -60,7 +60,7 @@
 "name": "_part.stem"
 }
 ],
-"xAdvance": 528
+"xAdvance": 501
 }
 }
 }