Q: How can I expand the canvas in one direction rather than
two directions at once? Is there a simple way to make stretcher bars
that will accomplish this?
A: Your concern about this matter is certainly justified.
When a canvas sags, it sags mainly in one direction. Therefore,
restretching the canvas isn't necessary and can even be dangerous to
the painting.
Q: I have many good pieces of primed linen canvas that are
creased, and I can't smooth out the creases by steaming or ironing
them. Is there some other way to get rid of this problem and salvage
the linen?
A: Creases in oil-primed canvas should be examined carefully
so you can fully determine if the sizing or primer has cracked. If
cracks have appeared, then you must avoid painting on that part of the
canvas. If the crease hasn't cracked the primer or size, there are a
few ways to alleviate the problem.
One way is to simply stretch the canvas as you normally would, which
will eliminate the crease over a short period of time. The constant
pressure that stresses the weave perpendicular to the crease is often
sufficient in these instances. If, over time, the canvas sags a bit and
the crease reappears or gets worse, restretching will be necessary.