Does anyone have any experience with stretching Canvas? I watched some youtube videos and it doesn't seem too hard. You just need a staple gun, the stretcher bars and the strecher plier would be handy.

I recently got some 20x30 canvas printed thru a discount so it was cheap. This is my first time stretching and I was going to order some bars from Stretcher Bars, Canvas Stretcher Bars, Canvas Stretchers, Stretcher Strips | Rex Art Supplies they seem to be fairly priced.

If my canvas is printed 20x30 full bleed, am i supposed to buy bars that are like 18x28, so about 2 inches shorter?