There is still an ongoing controversy about putting a pastel directly up to the glass, with no spacers. Europeans have been framing this way for ages, with excellent results, …or terrible results, depending on which blog posts you read. Most framers and museum conservators will say do not allow the pastel to touch the glass. If you google a search like “framing pastel” you get a lot of references to framers and artists who mostly recommend that the pastel NOT touch the glass. If you google a search like “pastel framed touching glass” or similar, you get a few more hits that mention this controversial method. These two discussions on Wet Canvas have the most pertinent conversation about it:
Surprisingly, I couldn’t find much mention of this more recently than 2008, though I know the method is still used and I suspect more frequently than mentioned.
I personally have been framing all my small pastel works taped directly to the glass, as have many pastel artists that I know, with no detrimental effects to date. I believe the key lies in securing the glass properly so that nothing will slide, and keeping the framed work away from sunlight and moisture.
------------------------------
*UPDATE* June 2016: An additional search on this topic has found an excellent article by respected pastelist and instructor Richard McKinley:
(coincidentally posted one month before I wrote this post, I just hadn't found his article at the time!)
------------------------------
Pros and Cons:
I’ll list here some of the harmful effects (of placing the pastel against the glass) that I’ve heard about, and state my response. I’ll try to be as fair as possible.
“This can cause rubbing and smearing.” I secure the glass completely around all 4 edges of the painting, so that it has no shifting room at all. I have never had any indication of the glass moving and causing smearing, and I travel frequently with my paintings getting packed, unpacked, hung (sometimes dropped!) and transported in a moving vehicle. The only damage I’ve experienced with a painting that was framed this way was when strong winds blew over my sales shelf (at an outdoor art fair) on which I had hung a small painting on the front. It blew over not once but twice, in rapid succession (before I had time to grab the stakes and bungees), slamming the painting face down onto the hard ground. I did then see the ghosting of the image ‘squeezed’ out over the inside of the glass. However, I do believe that such an impact would have jarred pastel onto the glass even with spacers. And although the frame needed some touch-up repair, and the glass needed cleaning, there was very little repair needed to the painting.
“The painting can stick to the glass.” This may have been mentioned in regards to the mold problem, addressed below, and if so, I would think that the mold would be the bigger issue by the time the glass was sticking! Or it might just have to do with the fact that you can sometimes get a ghost image on the glass when you remove it if you need to un-frame the painting. I’ve seen this in varying degrees, usually quite faint as to be hardly noticeable, and never to a point of making any difference in the painting itself.
“This contact condenses moisture that can cause the growth of mold.” I admit that there may be factors that I’m not experienced enough with to deny this statement completely. However, I have researched extensively online and found only 6 references by people with direct experience of mold on pastel paintings, and none have indicated specifically that the glass was touching the painting in any case.
One indicated the climate: “We live in the Tropics and have had extreme weather conditions, very humid and unbelievable flooding rains. …the glass got broken and didn't get it replaced right away.”
One was an old painting on canvas: “I recently bought a painting that is a Pastel, done in 1904, …It was under glass, which was moldy, and I wasn't sure if there was much mold on the painting
or not, but there is quite a lot. It is on a canvas material.”
One was a recent painting hanging on an outside wall: “I painted a picture... He had it professionally framed. It has formed mold dots... The picture is only about 2yrs old and hanging with other paintings of mine in the same house in the Catskill mountains (NY). It is hanging on an outside wall. All the other pictures are under glass except the oils and not hanging on outside walls.”
Another was a blatant mistake on the owner’s part: “…The owner left it in an environment for 3 months that encouraged a tropical forest climate complete with condensation due to extreme hot temperatures outside offset by a full-blast freezing AC running 24/7”
I found on another post, 9 rules for guarding against mold on artwork, and using a spacer under the glass is just one of them – not the only one! The way I see it, if the surrounding environment is conducive to mold, it could just as likely appear on a painting with spacers, as without. There are so many other variables; should the painting ‘breath’ under the glass or should it be sealed completely? Does sealing completely trap in moisture or seal it out? How do certain papers or canvas or boards retain or resist moisture compared to Gatorboard and acrylic primer? Only time will tell (– and scientific testing.)
“…the possibility of condensation and subsequent staining should there be a rapid drop in temperature.” It sounds like this is another way to phrase the mold issue. I have seen condensation appear rapidly on a framed pastel in direct sunlight – both outdoors and indoors. I’ve actually seen this happen on pastels with frame spacers and not without; I’m pretty careful to keep my original paintings out of sunlight while at fairs. (The condensation I’ve experienced has been on larger works with frame spacers, that I sometimes will hang on a side of my booth on a cloudy day – if the sun peeks out I’ll check the painting often and move it to shade when I see condensation. It always dissipates after a few minutes and I’ve never had any mold growth as a result. I can’t actually remember leaving one of my smaller ‘un-spacered’ paintings in sunlight to notice the development of condensation, so I’m conducting an experiment this week with an old ‘reject’ painting. I’ll update this post as it progresses.) As for the “…rapid drop in temperature,” I’m not sure if that should instead be “…rapid rise in temperature.” I did put my ‘experiment’ in the fridge today, and didn’t notice any change. I then moved it to the back porch (not in direct sunlight, but it was about 90 out at the time) and saw the condensation appear – on the outside of the glass – like it will on a camera lens in similar conditions. The condensation dissipated after just a few minutes. My next step is to leave it out all night and look at in in the early morning. Then I’ll let it sit in the sun for a while.
I also frequently leave my smaller paintings in boxes in the garage between shows, which is not at all like a wet basement, but it’s not air conditioned either, and is subject to some of the temperature and humidity changes of the outdoors. I’ve not seen any detrimental effects of this habit, but then south Texas doesn’t get the moisture that many other areas of the country do.
If you experience problems with mold on pastel, The Art of Pastel Painting By Alan Flattmann contains informative instructions on mold removal and prevention.
My “Spacer-Free” Method:
I use J-Lar acid-free clear tape (used for book repair) around all four sides of the glass, about 1/8” on the front of the glass, and secured around to the back of the painting support. This assures that the glass won’t move over the painting surface.
Because I use Gatorboard as my painting support, which is completely rigid and won’t bend or warp, no other backing is necessary. I simply slip this package into the frame and secure the back. Then paper, wire, and bumpons complete the job.
Frame Spacers:
If you're still unsure about any issues involved in this controversy, just use the frame spacers. You can find them at www.frametek.com. Just keep in mind this will increase the depth of your 'picture package' and unless your frame is deep enough, you might need offset clips to secure the back. I do use spacers on paintings larger than 11x14.
