When buying a canvas, how do you know what size to buy for stretcher bars?

Question

Do i buy stretcher bars that are the same size as what the canvas is, or do i buy couple inchs smaller. I am unclear if my canvas says 12 by 15 if that means the size it will be when framed?

Answer 1

The stretcher bars are the same size as the inner dimensions of the frame (ie. 12 X 15 frame will hold a 12 X 15" stretched canvas, using 12 X 15" bars).

For standard (3/4" deep) bars, you'll need the canvas about 4" larger on each side - leaving 2" all around to wrap around the stretcher bars (12 X 15" bars = 16 X 19" canvas). To get the tightest & most secure finished product, the canvas should be stretched right around sides and stapled onto the back of the bars.

Answer 2

Measure the width of each stretcher bar and add that to the length of each stretcher bar, as to properly stretch the canvas you will have to stretch it just over the back of the frame. ie- if you want a 12"x15" painting, and say the bars are 3 inches wide, you will need at least 18"x21" of canvas. Also remember to prime it with Gesso after you've stretched it.

Answer 3

you need to have the canvas larger then you're frame so you have enough to tack to the back of the stretcher frame and so you have enough to grip the canvas with your canvas pliers in order to stretch it over frame