Can I print a packing slip without prices to put in the parcel?

Wcart doesn't have a separate packing slip yet. The only printable document is the invoice from Print invoice on the order page.

You can make a lighter version for parcels:

1. Go to Settings → Store Settings → Invoice Templates and click New template.
2. Enter a Template name, such as "Parcel slip", and build the Template HTML with only the customer, address and items placeholders, leaving out the totals.
3. Save it, then click Set active when you want to print slips.

The items table always includes the price columns, so the line prices still show. Only the totals can be left out.