It is worth the extra charges to have your cover made with premium thread and canvas. Plus the fasteners, especially at the mast end should be as high quality as the maker offers. I purchased a "stock" cover with the cheap thread and it was less than I expected, after one season it was showing surprising amount of wear. Fortunately I had the craftsman that built my dodger re work the mainsail cover underside to fit correctly. He also re stitched the cover with the higher quality thread. I was lucky to employ such a wonderful professional, but, of course he made it up with the cost of the dodger... which is a real show stopper.