I don't do a lot of canvas work, but I just recently completed two 36"x36" pieces and ran into a problem I've had before. I've ordered "heavy duty" stretcher bars from several well known manufacturers and I still have the problem that they don't always fit together properly. I can usually get them to square up, but even then the corners don't always mesh perfectly and sometimes when stretching, one of the pieces will move. It's very frustrating and sometimes leaves a bump on one of the edges.
Any suggestions? Am I doing something wrong? Theses latest bars were from Utrect. I also tried some from Daniel Smith, with similar results.
-Max