If the image you’ve uploaded is pretty tiny and doesn’t fit the product templates, this means your image is not large enough to print on the physical product.
We’d recommend uploading an image that is at least 9075 x 6201 pixels. This will cover the entire range of products offered on the Redbubble marketplace.
You are welcome to offer a limited selection of products if you are unable to work with larger files.
Check out the dimension requirements for all products here.