Is mounting on linen archival?

Terry Hart cpf

SGF, Supreme Grumble Framer
Sep 23, 2003
Excelsior, MN
Is it? Or is it just something that's being done as a way to mass market old posters. Do these posters have real collectable value? What sort of adhesive is being used & what type of linen? Is this "preservation technique" accepted and practiced by conservators or how would they handle it? Seems to me that in a frame shop the best (only?) conservation method would be rag board and museum hinges. If true conservation wasn't the main concern maybe artcare restore. I'm sure a framer could mount a poster to a linen with an adhesive film but I'm sure it wouldn't be easily reversable. Is the mounting of these posters on linen that we've all seen reversable? I'ld hate to try, so how could they be archival?
Fabric backing (linen,cotton and sometimes silk) used to be a normal way to back paper that needed extra support.

In the mid 20th century, Japanese, and Japanese trained conservators introduced the west to Japanese paper backings. Thin paper backings are less intrusive, and the materials more compatable to the paper being backed than fabric.

This new system tended to be used more in North America than Europe, although that has changed in recent years. But, even today French conservators usually back posters with fabric rather than Japanese paper. French conservators are considered old fashioned (to put it mildly) by their European counterparts.

The people who back posters with fabric in North America were either trained in Europe, or got their own training from those following that tradition. I doubt you would find one conservator in North America who has done a fabric paper backing in the last 20 years or more.

Paper behaves differently than fabric, so the two adherends are not very compatible.

Adhesives are a whole different story. Wheat starch paste has a history in the west similar to Japanese paper - not in wide use till the '50's or so. In Europe, fabric backed posters were (are) applied with animal glue, sometime hardened with alum. Alum hardened adhesive are difficult/impossible to remove. Sometimes the adhesive is animal glue and starch paste.

According to one source, the fabric is stapled to a wall or board, and slathered with adhesive. The poster is then brushed on and left to dry. This results in a very stiff, flat poster.

Animal glue backings are messy and time consuming to remove, but not impossible, as long as there's no alum involved.

I've seen posters backed with a Japanese type paper interleaf between the linen and the poster. They said they used starch paste, but it looked "BEVA - y" to me. Or, it could have been some other type of dry mount tissue.

So, reversibility is unknown - sometime yes, sometimes no. There is no one way to apply linen backings, and without a treatment report there is no way to really know what was used.

In the interest of science, I called up the company I have used for this process. They use only wheat starch to mount the posters, and make their own from raw ingredients. The paper barrier between the poster and the fabric is called "Archivart", and the fabric itself is called "Cotton Duct Linen" (they spelled it for me over the phone) and they are going to phone me back about the cotton/linen content of the fabric.

They say that the process is completely reversible, and have removed and remounted a piece for me just earlier this year.