Yes, the Create-a-Product API only works on template products. Templates are instructions to Zazzle that let us know how to treat the various objects that you will send through the API, such as images and text. Without those specific instructions on where to place objects and how to size and scale them, we are unable to accurately portray the product. Here are instructions on creating product templates so that your products look exactly as you want them to, each and every time - https://help.zazzle.com/hc/en-us/articles/219145288-Creating-a-Product-Template