Framing an oil painting under glass

[604jenn]

I have an old (more than 20 years) oil painting. It was framed in a wood frame and no covering (no glass). I would like to re-frame it in a glass frame and have been reading various opinions on if glass can be used to frame an oil painting. I would prefer it to be under glass to protect it. The frame I have would not have the painting touch the glass (there is a bit of space). So, is it safe to have it under glass and do I need a special acid-free backing for the frame (the mat I have is "PH balanced")?
Thanks!

[DaveMak]

Framing an oil under glazing is actually the preferred preservation framing method.

It provides several benefits:

~ It protects the painting from physical trauma from the front and also helps protect the artwork from airborne pollutants.

~ If UV coated glazing is used, it also helps protect the painting from the most harmful UV rays.

~ It provides a micro environment allowing temperature and humidity changes to be more gradual.

You don't say whether the painting is on a stretched canvas or a panel. If it is a stretched canvas, you should also put a board backing on the verso side of the frame. This can be rag board, AF Foam Core or polyflute board. This protects the canvas from physical trauma during transport, seals the back to prevent insects and dirt from accumulating and also helps seal the microenvironment.

If it is a panel, then either use a board as outlined above or apply a paper or Tyvek dustcover.

The old adage that paintings need to "breathe" has been dismissed by conservationists.

A few other things that should be mentioned.

~ If the painting were somewhat freshly painted, and this one is not, then during the continued drying process some out gassing does occur and the frame package would need to be opened up down the line to clean any film on the glazing.

~ No artwork should be hung where the sun hits the artwork, but this is especially true of sealed frame packages. They can rapidly rise in heat and a sealed frame package could create a greenhouse effect making the interior heated. This can cause chemical change to accelerate.

~ I have been using the term glazing instead of glass or plexiglass because the preferred glazing would be an optically coated acrylic plexiglass. Acrylic glazing is not nearly as breakable and if you use glass there is a danger of breakage which could cause physical damage to the painting.

One last point... your "pH" balanced board indicates that it is a buffered board. This creates a temporary "acid free" status which is not all you should be concerned about. Buffered boards eventually become acidic. Also, another chemical mix in the board would be lignins which are wood by-prodcuts which also are not something you want near any artwork. The rule of thumb is to keep all such materials at least 1" away from the artwork to prevent migration of harmful chemicals.

[DaveMak]

Having said all of the above, my personal preference is not to use glazing on oils except in a public environment. I prefer varnishing with a synthetic removable varnish such as W/N's Con-Serve art varnish.

Oil paintings are quite tactile and I fell that most glazing detracts from this element of enjoying the art.

When using glazing I would recommend either TruVue's Museum Glass or Optium Acrylic.

Three factors to consider in glazing for framing:

~ The visible light transmission. How clear is it and how much of the visible light does the glazing allow to pass through without changing it's color.

~ The amount of UV protection.

~ The reflectivity of the glass.

TruVue's Museum Glass and Optium Acrylic provide the highest standards in all three categories.

[Tonalist]

I have an old oil painting.. It is not dated, by I can pretty well assume it's about 80-90 years old. It is framed in the original wood frame which has glass and still looks good.

The painting itself does not touch the glass, painted on some type of panel and it did have a dust cover which no longer exist.

I thought about getting it reframed.. but I simply don't want to get rid of the old frame.

[DaveMak]

Not sure what your thoughts are about reframing but if the original frame is in good condition then I would consider having the painting taken out, the glass cleaned and put back in with an intact dustcover to prevent insects and dirt from accumulating in the back.

The frame itself could be rejuvenated if necessary. If there are any compo ornaments missing they can be replaced, corners, if loose can be rejoined and the frame could be touched up or even re-gilded.

Old frames original to the artwork are, IMO, worth saving.

[Tonalist]

Thanks dave..
Yes, I plan on keeping it in the original frame. The frame does make it look older, mostly because of the style. The frame is in pretty decent condition.. I do need to get the glass replaced.