You may be surprised to learn how to mount a canvas print is a fairly flexible endeavor.
You can mount a canvas print without stretching it. There are two techniques: wet mounting and dry mounting.
Wet mounting means using a liquid adhesive to adhere the canvas to a rigid substrate. Dry mounting involves using a film laminate to stick the canvas to the rigid surface.
When working with canvas specifically, it is best practice to use the wet mount method. If you are mounting a smoother media, such as photo paper, then dry mounting is common and often easier.
But in truth, one process is no better or worse than the other. They merely come with their own distinct pros and cons.
With the wet mount process, you basically mount the canvas to Gatorboard to give the finished piece its rigidity. Of course, you could also mount it to MDF, Masonite, or some other rigid substrate. Gatorboard is dense, durable, and relatively lightweight. This allows for a simple, damage-free workflow as well as safe transport or shipping to the client.