I frequently use Senior Arts Eaglemont for custom stretched canvases because my studio isn't set up to allow me to do my own stretching for the larger-scale canvases that I prefer to use. The HD stretcher bars are good quality and have never warped in my experience. There is a great choice of Claessen's linen. Value for money is excellent, much more affordable than other services I have tried. The $20 flat rate delivery fee is also great value if you are ordering large and/or multiple canvases.