Mounting clip for canvas

My wife is an artist and i make a lot of frames for her.In oak, elm, ash and so on. But i think it was hard to mount the frames on the canvas in a safe way. So i made these clips. Realy simple and sturdy. There is 7 different clips in the file. One plane, and 1-6mm offset.My suggestion is that you print the file and test on your combination of frame/canvas.Then print as manny as you need of your desired offset. I recomend that you print in PETG.