Hello all, my institution has just had quite a bit of turnover in our collections department, and I (objects preparator, and printmaker by trade) am being asked to add backing boards to several paintings in our collection that do not have them. Our conservator is also new, and a paper specialist (go figure, we're both paper people) and does not have experience backing stretched paintings within frames. Our intention is to use blue board, but it seems the previous preparator used non-reversible/permanent methods for fixing boards to the back.
Long story short, is there a reversible way to mount a backing board to a stretched painting in the frame without drilling holes? Thank you in advance!
Hi David, thanks for the pro tip. That is good advice. -Scott
In addition to the great advice from Scott, I'd just add one more small point. When attaching the backing board to the stretcher bars, make the holes in the backing material oversized. This will allow for expansion of the stretcher bars as they are keyed out and expanded in the future.
As a professional picture framer for the past 35 years, as well as head framer at a large regional art center for 9 years, I'd like to weigh in.
A backing board can be placed as the final element of a framed painting, but many times a canvas isn’t framed. A backing board on a painting is important for several reasons. It lessens the air chamber behind the painting and keeps the canvas from billowing excessively during transport or changes in atmospheric pressure, say when doors of buildings are opened. Reducing this movement reduces strain on the paint applied to a flexible surface. Backing boards also provide cheap insurance against puncture, because even though we are all professionals, we can’t be in all places at all times. Also, backing boards help stabilize the stretcher frame, which should be a fluid assembly to allow for adjustments. (If the corners are glued and fastened, you’re looking at a strainer, which is a different thing but is often used as a stretcher. In any case, the first two benefits still apply.)
Installing a backing board should be a standard step in the construction of a stretched canvas. If the original framer or preparator hasn’t done so, or if the original backer has been lost to history, you should consider adding it as part of your job, whether you do it yourself or contract it to a qualified framer.
Coroplast is the backing board of choice these days, due to favorable chemical composition (polypropylene), rigidity, resistance to puncture, and availability. We used to love blue board for similar reasons, but several years ago availability (especially in large sizes) became difficult.
Attaching the backing board is a compromise. In order to be effective, the backing board has to be secure. Most backing boards are screwed to the back of the stretcher frame.
Use screws that won't go through the front of the painting (!) and use finish washers to keep the backing board from pulling away over the screw heads. Depending on the size of the stretcher frame, it doesn't take that many screws to secure the board. Many adhesives will leave permanent damage that can and should be avoided.
Another caveat: try to position the screws so that they only pierce the stretcher frame itself, not the canvas of the painting. Sometimes this isn't possible, but typically the area where you'd put screws is past the point where the artist (or framer) stapled the canvas to the stretchers anyway. A relatively small screw hole is not dissimilar from a staple or tack hole, and the benefits of having the structural support, movement baffling, and puncture protection of a backing board far outweigh the costs.
I hope this helps.
Hi June. By blue board do you mean archival cardboard or cloroplast (sp?)?
Either way, to avoid drilling holes, you'd have to use a frame that could accommodate a bracket system. That way you can sandwich the stretched canvas and the backer board together.
You may need to add some felt or the like (depending on the condition and material of the frame) to snug everything up or as a type of gasket. Archival framer tape if you need a seal on the back, then engage the brackets.