Brilliant, thanks! This just made my day 
Topic summary
Users are seeking ways to alphabetically sort items on Shopify packing slips, particularly challenging for orders with 100+ items.
Solution Found:
Multiple users confirmed a working code modification in the packing slip template (Settings → Shipping and Delivery → Edit Packing Slip Template, around line 97).
Working Code:
Replace:
{% for line_item in line_items_in_shipment %}
With:
{% assign lineitems = line_items_in_shipment | sort: "title" %}
{% for line_item in lineitems %}
Additional Findings:
- The code can be modified to sort by SKU instead of title by replacing “title” with “sku”
- Browser caching may show old versions when testing; try different orders to verify changes
- Some users reported spacing issues after implementation, with items potentially printing outside margins on multi-page slips
Unresolved Questions:
- How to sort by additional attributes like color/Option1 Value after initial title sort
- How to group by product type with alphabetical sorting within each group
- How to fix increased spacing/margin issues that waste paper