Prodigi

Prodigi operates as a print-on-demand infrastructure layer, handling fulfillment and logistics for resellers who want to offer custom merchandise without holding stock. Their catalog spans over 500,000 products, from ceramic mugs and tumblers to phone cases and canvas bags. The API integration lets you build mugs directly into your storefront, with Prodigi managing production and shipping.

This works well if you're building a custom brand or marketplace and need a production partner that stays behind the scenes. You'll find better margins than retail POD platforms, though you'll need technical skills to integrate the API. Spreadshop or Contrado might be easier if you want a ready-made store instead.