Julie here from Shopify Support.
Is there a reason why you're wanting to use a print on demand app if you plan on designing, printing, and shipping products yourself? To clarify, print on demand is a form of dropshipping that allows merchants to sell products that are printed and shipped by third-party suppliers.
The purpose of print on demand is to make the fulfillment process hassle-free and more affordable, since you won't need to purchase inventory upfront. Instead, you only need to pay for a product when a customer purchases one from your online store. Then, a third-party supplier will handle the printing and will ship the product to your customer on your behalf. Since you intend to handle this on your own, it's likely that you won't need a print on demand app. I suggest checking out our blog post, "Print on Demand: A Low-Risk Way to Sell Custom T-Shirts, Books, and More" if you'd like to learn more about print on demand and whether it's the right fit for your business.
Are you instead wanting an app to create images of what your designs will look like on your products? If so, there are a few ways you can do this without the use of print on demand apps. First, you could choose to use an app like Mockupify, which is specifically intended to provide merchants with product mockups. With this app, you'll be able to upload your design, choose a product, and download images of your design on those products so that you can use them in your online store.
Alternatively, a quick Google search for "product mockup generators" provides a few more options from third-party websites, including Mediamodifier, Smartmockups, and MockupBro. Like the Mockupify app, all of these websites allow you to upload your own designs, choose products, and download mockup images.
If you plan on selling t-shirts, then I suggest checking out our blog post, "Design Your Line: 19 Ready-To-Use Online T-Shirt Templates and Mockups" for even more options, including downloadable product templates that you can use to build your product mockups. Keep in mind that these downloadable files will require access to and a basic understanding of image-editing software.
I hope this guides you in the right direction, but If I've misunderstood you're question, please let me know; I'd love to get a better sense of why you are wanting to use a print on demand app so I can offer some suggestions.
Looking forward to your response!
It's Melissa from Contrado here, I hope I can help with your question.
Contrado is a print on demand company with more than 450 products for you to design. We handmake everything to order so that you can use it for your brand.
You can use our app to preview your designs and create mockups. Once you've designed the products, you can purchase them to fulfill the orders yourself or sync with your Shopify website.
Let me know if you have any questions
Melissa from Contrado
Get the Contrado app for Shopify: https://apps.shopify.com/contrado-print-on-demand