How to Prevent Warpage in Canvas Stretcher Bars??

Hi,

I had the first canvas that i ever stretched warp on me, especially when i had the tension of canvas on it.

I have since re-stretched it on a new one, that has a bracer bar on the back, which is what i needed.

However, i have made another one with the bracer bar (plus two particle board 'triangles', that is also warping a slight bit, although not even as bad as the first.

Do you folks have any tricks for keeping the stretcher bars from warping (i.e., one corner would stick up when it is against a flat surface), or a method of straightening things out if they do warp a bit?

Thanks in advance!

Fasten metal corner plates to straighten these bars. Use short daywall screws instead of wood screws.

are you using premade strtchers? if so the cheap or heavy duty ones? if your making your own strtchers was the wood warped a little before you cut them? on the other hand, is this something that is obvious when it is hanging on the wall or are you inspecting for perfection horizontal on a flat surface? the worst problem I had was with those 'masterpiece' stretchers, the wood is so soft the corners can mash just hammering em together. i sold a painting that these people mounted on a panneled wall, i.e., parallel lines on either side of my canvas, emphasizing it's lack of geometric perfection. i took the painting back, made a new strtcher and restretched the canvas (i had to retouch the painting on one edge) and returned it to the happy couple. since then I am aware of the imperfection, sqaure and flat, of my paintings but i endeavor to make them as perfect as i can. most, almost all, once framed and hung don't look imperfect...

I'm sure the heavy duty (thick) ones have less of a problem.

I used the pre-cut (Masterpiece) ones, but i always check them for straightness before i buy them.

I inspect them from the side, eyeballing the two corners to see if one pops up...or i look to see how parallel the edges are.

the worst problem I had was with those 'masterpiece'

Right, the Masterpiece stuff is a bit flimsy. And you are right, a slightly warped canvas should straighten out once you put a decently thick frame on it..

Thanks for your input...