How Strong Is It? No Really . . .
Just for my own information I soaked one of my mounted watercolor paintings in a bathtub of water, and left it floating on top overnight. Not even a smidgen of paint soak off into the water, nor did any of the paper loosen from the canvas.
So, I then drowned it totally with water, filling the back side with water as well. The entire canvas was weighted down and under water, again leaving it overnight. This time, paper did begin to bubble up from off of canvas backing where it was beginning to loosen. But it took the water actually penetrating through the canvas, back to front, for paper to move.
This photo is what was left of the original watercolor paper, which had been mounted onto Gallery Wrapped Canvas, after I worked at stripping paper off. And believe me, it did take work . . .
P.S. Painting I used for this test had already been ruined during process of painting. Just decided to mount and test for the purpose of seeing how strong these Watercolor's mounted onto Canvas actually are.