Canvas stretcher bars have been used by Artists since the dawn of time! Of course back then the stretcher bars were not as refined as they are today. In fact a simple frame of four pieces of wood will give you a basic frame to stretch over however you need to consider strength and stability when performing D.I.Y. manufacture of stretcher bars. Today's ready made stretcher bars are made with high tolerances to give snug fitting joints, that funnily enough are able to move. Most bars today, are made from Firwood (from Asia) although some are made from European Pine and other woods from around the world.
What sizes do I need?
Stretcher bars are sold in PAIRS
. Therefore if you are framing a piece of canvas then you will need to purchase TWO
pairs. So imagine you are framing a canvas of about 14" square then you will need two pairs of stretcher bars at 12". Why 12"? and not 14"?...Well... because you will need to wrap the canvas around the side wall and to the back of the frame and then staple onto the back side of the canvas stretcher bar. Therefore you need a margin of canvas to fold round the back.
You can of course staple on the side wall of the stretcher bars however painting on the side wall is very 'in vogue' at this time so stapling/nailing the canvas onto the back side is preferred.
SHOW ME HOW TO stretch a canvas
You can see many versions of how to stretch canvas on YouTube by following this link SHOW ME HOW TO stretch a canvas