You can generate the printed catalog grouped by category.
When doing this it is common to want to order the categories in a specific order. By default the categories will simply be listed in alphabetical order.
If you look at the item category list you will see a Sort Index field that can be used to adjust this ordering:
The categories will be sorted first by sort index and then by name.
This means the categories you want to come first should have a lower sort index defined and those categories you want to appear later should have a higher sort index value defined.
You can adjust the sort index directly from the item categories list (see Edit Rows) or double click on a row to drill into its details.