Hello, I want to glaze (plexiglas) my paintings. What kind of rigid panel should I attach the canvas to that doesn’t hold too much moisture beneath the finished painting? Hardboard is heavy and can warp. ACM can be expensive or tricky to glue canvas to. Does glueing the linen to the support using acrylic medium attract extra moisture? Will framing behind glazing restrict the oxidisation of the paint? How much space is needed between the glazing and the painting and a rear board?
That is a goodly number of very pithy questions. To begin, the concern with oxidation implies that the painting is in oil and anything that limits the exposure of the paint surface to oxidants will slow the oxidation, but that may result in a more stable film, ultimately. There is likely to be an issue with effluent from the oxidation reaction accumulating of the glazing sheet and that will require periodic cleaning. If the fabric is to be adhered, then gloss acrylic is a good option, as are aluminum/plastic panels, and the acrylic adhesive will be hygroscopic, but less so than the fabric, itself. The aluminum will block moisture from the verso and the fabric is not likely to cause the panel to warp, as an adhered sheet of four ply board can do. It makes sense to space the glazing sheet by a quarter of an inch, using radiation cross linked polyethylene foam (Volara) that is attached to the glazing sheet and while acrylic sheet (PMMA) will allow water vapor to pass through it, it should not affect the painting, but if the seal at the spacer layer is very tight, there may be some warping of the glazing. Wood based boards should be avoided, since they can become infested, with pests, in the long run. Since you are the artist, I have been thinking that you would be making the panels and then painting them. Hugh Phibbs
Hi Kristin, thanks. The intention is to to prepare a number of panels before I paint. I don’t intend to adhere a completed painting to a rigid support but if I that happened, I’d ask framer to vacuum seal linen onto a panel rather than stretch onto bars, as soon the painting is dry enough. How does sound? Thanks very much for the details Hugh. yes I should have mentioned oil paint. I had read that it might benefit from slower oxidisation under glazing. Interesting about the haze /effluent. Hopefully that would be very slow to occur and only need normal methods to clean plexiglas
Just to clarify, it sounds as if you want to try and adhere your completed painting to a rigid support, something that can be risky to perform. I would worry about attempting such an operation far more than interfering with paint oxidation and/or creating a potential moisture barrier via glazing. If you are attempting to do so we can do our best to give advice regarding this process but in general we do not recommend doing this. As for glazing interfering with paint oxidation I would not be too concerned about this. The paint will dry no matter what albeit somewhat slower if it is truly sealed (you would be surprised…simply placing plexi over the surface does not by itself prevent airflow). Every great once in awhile we see a slight haze begin to accumulate on the reverse of the glazing (plexi side facing the painting). This hazy film has been tested and found to be free fatty acids re-depositing from the paint film onto the glazing. This can simply be addressed by occasionally removing the glazing and giving a good clean. I would also not be concerned about glazing potentially causing a buildup of moisture (and no, acrylic gel medium/adhesive will not cause a problem here) as again there will be a slight airflow unlesss you have a professional framer create a sealed climate package (as is sometimes done for paintings in museum collections). We can reach out to our resident framing experts on this one as I may be missing something.
Yes…having someone use a heated vacuum table to attach a completed painting onto a rigid support is what we recommend. You can ask your framer to do it (if they have such a device) or your local conservator.
