Vistaprint? They're a massive German operation - mind you every town has at least one print shop but VP already has a custom printing system, their parent company have a print fulfillment API (https://open.cimpress.io/).
[Just an occasional private customer]
Cool. How do you process payments via text? I assume you send them a link to a page to complete transaction?
Exactly. I looked in to charging via their phone bill but couldn't find an API.