Spread canvas on a clean, flat surface with the primed side down.
Place wood frame on top of it.
Wrap canvas edge over one of the short sides of the frame. In the middle of the stretcher bar--side of wood frame--attach the canvas with the staple gun.
Pull the canvas over the opposite side of the frame's edge. Use canvas pliers and pull canvas tightly over the frame edge. Apply staple in the center of the stretcher bar.
Repeat steps 2 and 3 on the each of the long sides. Using your pliers to stretch the canvas, and your staple gun to attach. The canvas should be attached now with a staple in the middle of each side.
Apply a second staple in the middle of the space between the corner of the frame and your first staple. Put a third staple in between the other corner and your first staple. There will be three staples now, evenly spaced, on the side you started with.
Go to the opposite side and repeat. Do the same with the other two sides. Make sure that you are stretching the canvas before each staple to make sure it is taught.
Continue stapling canvas to the stretcher bars, placing staples evenly, working with one side and then its opposite, until there are staples all the way round 1 to 2 inches apart.
Choose a corner. Pull the corner of canvas over the corner of the frame tightly. Staple it to the frame. There will be two "wings" of canvas on each side.
Tightly fold in wings, one over the other.
Staple them down to the frame.