Printful is a print-on-demand dropshipping service that can be used by designers, artists, sports teams, musicians and others who want to sell branded products or merchandise. It is integrated with your shop via the Printful app. You can find the Printful app in the App Market of your shop settings.
After installing the app you can choose from a range of products in Printful such as t-shirts, hoodies, hats (embroidery), posters, photo prints, canvas, mugs, etc. You can apply your graphics to the chosen products, set your margin on top of Printful prices and publish the products in your Ecwid store.
When a customer places an order for such a product, Printful will be automatically notified of a new order. It will print your graphics on the ordered product, pack it and send it to the customer in your name.
Here you can find the detailed instruction on the app setup: Printful: Dropshipping for Custom Print Products.
The app is free to sign up and you only pay when an order is made.