diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 94182d7..466c047 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -54,7 +54,7 @@ jobs:
       - name: install iris-grib
         run: |
           source $CONDA/bin/activate base
-          conda install -y -c conda-forge iris-grib
+          conda install -q -y -c conda-forge iris-grib
       - name: generate index
         working-directory: indexing
         run: |
diff --git a/indexing/INDEX_template.md b/indexing/INDEX_template.md
index 0b0da8d..4a7687c 100755
--- a/indexing/INDEX_template.md
+++ b/indexing/INDEX_template.md
@@ -1,18 +1,21 @@
-{%  for prefix, data in content.items()%}
+{% for prefix, data in content.items() %}
 
 <details>
 
   <summary>{{ prefix }}</summary>
 
-  {% for filepath, link_path, cube_strs, warnings, exceptions in data %}
-  # [{{ filepath }}]({{ link_path }})
+  {% for filepath, link_path, items, is_png, warnings, exceptions in data|sort(attribute="path") %}
+  #### [{{ filepath }}]({{ link_path }})
 
-  {% for cube_str in cube_strs %}
+  {% if is_png %}
+  ![{{ link_path }}]({{ link_path }})
+  {% else %}
+  {% for item in items %}
   ```
-      {{ cube_str | indent(first=False) }}
+      {{ item | indent(first=False) }}
   ```
   {% endfor %}
-
+  {% endif %}
   {%if warnings %}
   ```
   {% for warning_str in warnings %}
diff --git a/indexing/generate_index.py b/indexing/generate_index.py
index e432477..e5c0039 100644
--- a/indexing/generate_index.py
+++ b/indexing/generate_index.py
@@ -1,13 +1,13 @@
+import warnings
 from collections import defaultdict
-from jinja2 import Environment, FileSystemLoader
-import os
 from pathlib import Path
 from typing import List, NamedTuple
-import warnings
 
 import iris
+from jinja2 import Environment, FileSystemLoader
+from PIL import Image
 
-IGNORE_SUFFIXES = [".py", ".rst", ".txt", ".md"]
+IGNORE_SUFFIXES = [".cdl", ".gz", ".md", ".npz", ".py", ".rst", ".txt"]
 
 TEST_DATA_ROOT = Path(__file__).parent / Path("../test_data")
 TEMPLATE_FILE = Path(__file__).parent / Path("INDEX_template.md")
@@ -17,7 +17,8 @@
 class FileInfo(NamedTuple):
     path: Path
     link_path: Path
-    cube_strs: List[str]
+    items: List[str]
+    is_png: bool
     warnings: List[str]
     exceptions: List[str]
 
@@ -33,22 +34,34 @@ def getDataFilepaths(path: Path) -> List[Path]:
 def getFileInfos(filepaths: List[Path]) -> List[FileInfo]:
     file_infos = defaultdict(list)
 
-    for filepath in filepaths:
+    for filepath in sorted(filepaths):
 
-        cube_strs = []
+        items = []
+        is_png = False
         warning_list = []
         exception_list = []
 
         with warnings.catch_warnings(record=True) as ww:
+            print(f"{str(filepath)}")
             try:
-                cubelist = iris.load(str(filepath))
-            except Exception as e:
-                print(f"Error loading {filepath}")
-                exception_list.append(f"{type(e).__name__}: {e}")
-                print(exception_list[-1] + "\n")
-            else:
-                for cube in cubelist:
-                    cube_strs.append(str(cube))
+                image = Image.open(str(filepath))
+                if image.format == "PNG":
+                    is_png = True
+                    items = None
+                image.close()
+            except IOError:
+                pass
+
+            if not is_png:
+                try:
+                    cubelist = iris.load(str(filepath))
+                except Exception as e:
+                    print(f"Error loading {filepath!r}")
+                    exception_list.append(f"{type(e).__name__}: {e}")
+                    print(exception_list[-1] + "\n")
+                else:
+                    for cube in cubelist:
+                        items.append(str(cube))
 
             for warning in ww:
                 warning_list.append(f"{warning._category_name}: {warning.message}")
@@ -59,7 +72,8 @@ def getFileInfos(filepaths: List[Path]) -> List[FileInfo]:
             FileInfo(
                 filepath.relative_to(TEST_DATA_ROOT),
                 filepath.relative_to(OUTPUT_FILE.parent),
-                cube_strs,
+                items,
+                is_png,
                 warning_list,
                 exception_list,
             )