How to stretch canvas is a skill that can save you money. Stretching and priming your own canvas give the art a new look, an old world look and extend the work to craft. It's fun.
HOW TO MAKE A STRETCH CANVAS FREE LESSON Learn how to make a large canvas art
Here also is a great article which counters the traditional methods. I like the use of pushpins and the approach where he starts at the corners. Very interesting.