diff --git a/src/processing_steps/0300_volume_matcher.py b/src/processing_steps/0300_volume_matcher.py
index a9c7d6a..3dd4c9f 100755
--- a/src/processing_steps/0300_volume_matcher.py
+++ b/src/processing_steps/0300_volume_matcher.py
@@ -1,3 +1,7 @@
+#! /usr/bin/python3
+'''
+Script for matching volumes from the top and bottom of a multi-scan tomogram.
+'''
 import sys
 sys.path.append(sys.path[0]+"/../")
 from config.paths import hdf5_root
@@ -16,25 +20,26 @@
 #    - should probably be removed by kernel-operation around outer edge, before matching...
 
 ###########################
-### Fix shifted volumes ###
-###########################
+    '''
+    Find shift that minimizes squared differences with `overlap <= shift <= max_shift`.
+
+    Parameters
+    ----------
+    `voxels_top` : jp.array[Any]
+        The top region to match.
+    `voxels_bot` : jp.array[Any]
+        The bottom region to match.
+    `overlap` : int
+        The overlap between the regions.
+    `max_shift` : int
+        The maximum shift to consider.
+
+    Returns
+    -------
+    `result` : Tuple[int, float]
+        The shift that minimizes the squared differences and the corresponding error.
+    '''
 
-import h5py, sys, jax, os.path, pathlib, tqdm
-import numpy as np
-import jax.numpy as jp
-import h5py, jax, sys
-from PIL import Image
-sys.path.append(sys.path[0]+"/../")
-from config.paths import hdf5_root
-from lib.py.helpers import commandline_args
-
-verbose = 1
-volume_matched_dir = f"{hdf5_root}/processed/volume_matched"
-
-def match_region(voxels_top, voxels_bot, overlap, max_shift):
-    """
-    Find shift that minimizes squared differences with overlap <= shift <= max_shift
-    """
     # Shifts smaller than the overlap overlap with shift
     slice_size = voxels_top.shape[1]*voxels_top.shape[2] # Normalize by number of voxels (to make sums_lt and sums_ge comparable)
     sums_lt = jp.array( [ jp.sum(((voxels_top[-shift:] - voxels_bot[0:shift])/(shift*slice_size))**2)
@@ -53,6 +58,24 @@ def match_region(voxels_top, voxels_bot, overlap, max_shift):
 
 
 def match_all_regions(voxels,crossings,write_image_checks=True):
+    '''
+    Match all regions in a volume.
+
+    Parameters
+    ----------
+    `voxels` : np.array[Any]
+        The volume to match.
+    `crossings` : np.array[int]
+        The crossings between the regions.
+    `write_image_checks` : bool
+        Whether to write images to check correctness.
+
+    Returns
+    -------
+    `shifts, errors` : Tuple[np.array[int], np.array[float]]
+        The shifts that minimize the squared differences and the corresponding errors.
+    '''
+
     shifts = np.zeros(len(crossings),dtype=np.int32)
     errors = np.zeros(len(crossings),dtype=np.float32)
     match_region_jit = jax.jit(match_region,static_argnums=(2,3));
@@ -91,9 +114,27 @@ def match_all_regions(voxels,crossings,write_image_checks=True):
         del bot_voxels
     return shifts,errors
 
-# Copy through the volume matched volume from the original - general interface
-# that works equally well for anything indexed like numpy arrays - including cupy, HDF5 and netCDF.
 def write_matched(voxels_in, voxels_out, crossings, shifts):
+    '''
+    Copy through the volume matched volume from the original.
+    - general interface that works equally well for anything indexed like numpy arrays - including cupy, HDF5 and netCDF.
+
+    Parameters
+    ----------
+    `voxels_in` : np.array[Any]
+        The original volume.
+    `voxels_out` : np.array[Any]
+        The volume to write to.
+    `crossings` : np.array[int]
+        The crossings between the regions.
+    `shifts` : np.array[int]
+        The shifts that minimize the squared differences.
+
+    Returns
+    -------
+    `None`
+    '''
+
     voxels_out[:crossings[0]] = voxels_in[:crossings[0]]
     cum_shifts = [0]+list(np.cumsum(shifts))
     crossings  = list(crossings) + [voxels_in.shape[0]]
@@ -105,9 +146,28 @@ def write_matched(voxels_in, voxels_out, crossings, shifts):
         if verbose >= 1: print(f"Duplicating unmatched part of subvolume {i+1}: voxels_out[{crossings[i]-cum_shifts[i]}:{crossings[i+1]-cum_shifts[i]-shifts[i]}] = voxels_in[{crossings[i]+shifts[i]}:{crossings[i+1]}];")
         voxels_out[crossings[i]-cum_shifts[i]:crossings[i+1]-cum_shifts[i]-shifts[i]] = voxels_in[crossings[i]+shifts[i]:crossings[i+1]];
 
-
-# Create and populate a volume matched HDF5-file from the original
 def write_matched_hdf5(h5_filename_in, h5_filename_out, crossings, shifts, compression='lzf'):
+    '''
+    Create and populate a volume matched HDF5-file from the original.
+
+    Parameters
+    ----------
+    `h5_filename_in` : str
+        The input HDF5 file.
+    `h5_filename_out` : str
+        The output HDF5 file.
+    `crossings` : np.array[int]
+        The crossings between the regions.
+    `shifts` : np.array[int]
+        The shifts that minimize the squared differences.
+    `compression` : str
+        The compression to use.
+
+    Returns
+    -------
+    `None`
+    '''
+
     h5in  = h5py.File(h5_filename_in, "r")
     h5out = h5py.File(h5_filename_out,"w")
     voxels_in = h5in['voxels'];