Archival impact from finish on wood frame

**Brian Sims** · 4-Oct-2006, 11:21

I am working on a project that will require the use of wood frames. The wood selected is connected to the subject matter. It is a hardwood that I can finish with linseed oil, shellac, water or oil-based varnish, even paste wax. The question is: which of these finishes would create the least outgassing of chemicals that might damage the matboard or the prints. I suppose I could finish the inner parts of the frame differently from the outside surfaces. I do need to finish all surfaces to prevent wood movement with changin humidity.

Advice?

**Ralph Barker** · 4-Oct-2006, 13:00

Usually, the inside surfaces of frames are left unfinished, with only the exterior, visible surfaces being stained and varnished. Thus, conventional finishing should have no more effect on the print than whatever else might be in the room atmosphere. Dimensional changes caused by humidity mostly affect the cross-grain dimension, with little or no change along the grain. Under normal display conditions, however, I wouldn't expect to see any substantial change in the frame's dimensions.

**Brian Sims** · 4-Oct-2006, 13:41

Thanks Ralph. The wood I'm working with (Madrone) is notorius for squirly movement. I'm not concerned about the long-grain dimensional changes. The risk is uneven expansion which will warp the frame so that it no longer lays flat against the wall. Sealing the wood on all sides will mitigate that risk. The question is what's the safest finish?

Someone else suggested some sort of tape that I could apply around the edges sealing the entire sandwich of glass, mat-window, mat-base. I'm not sure what kind of tape that would be?

**Arne Croell** · 4-Oct-2006, 14:34

The book by Siegfried Rempel " The care of photographs" advises generallly against wood, but specifically against oak. If wood has to be used, he advises an acrylic varnish. He and several others (Kodak: Conservation of photgraphs", Keefe/Inch "The life of a photograph") specifically advise against using any oil-based varnishes. Wax, specifically "Renaissance Wax" available through Light Impressions, is a possible alternative since it is recommended for use with photographs:
http://www.lightimpressionsdirect.co...23200&IID=8282

**Henry Ambrose** · 4-Oct-2006, 16:32

Shellac would be the most likely to NOT cause problems. Once its cured its pretty darn near inert. Of course alcohol will ruin a shellac finish, shellac will water spot and it scratches easily compared to varnish but your frames shouldn't get harsh treatment.

If I remember correctly Madrone is somewhat oily - shellac will help with that too as it sticks to most anything. Buy dry shellac and mix it with alcohol yourself - then you know whats in it.

**Jim Ewins** · 4-Oct-2006, 21:47

Dry the wood by placing it in a warm dry area for several months. Then place it in a location simular to that in which it will be hung to reach equalibrium. Madrona is beautiful.

**Brian Sims** · 4-Oct-2006, 22:33

Thank you all for the great advice. Arne, I ordered the book you recommended. Henry, what you say about shellac makes sense...I'll go with that. Jim, good point...I think I'll rip it oversized let it stabilize and then joint it to the final dimension.