This is Ren from the Shopify support team, thanks for your question! We do have an app integration that offers these multi panel wall art pieces.
Check out Printy6 on our app store. That being said, you don't necessarily have to use a pre-existing integration to sell on Shopify so if you find one suitable, it's always worth asking if they've developed or can develop an integration for your store to use.
On the topic of Print on Demand in general, check out this awesome resource for learning the in's and out's of what POD can offer you as well as the pros and cons you can expect with this business model. In the article you'll find a link to our Shopify Academy course for How to Build a Print on Demand Empire.
I hope that helps! Feel free to reply with any questions.
Please check the below companies suits your requirements.
Canvas on Demand