Mounting
Dictionary definition - Something that serves as a support, setting, or backing - or a framework used for support or display.
Mounting in terms of picture framing can run the gamut from fully adhering a piece of art work with most any type of adhesive on any type of backing as was often done in the past, to the gentle tipping/hinging of artwork with conservation materials to an archival backing. I, of course, would recommend the later. In general, fully mounting artwork is looked down upon in conservation work circles, perhaps because of so many horrible mounting/framing jobs done in the past, yet I find that some situations call for it without recourse. But, more on that later.
It seems older picture framers often fully mounted art to backing as it made for a more manageable framing package. It was easy to do, easier to handle, didn't move, laid flat, no ripples, for a better looking presentation & final product. In taking apart numerous older framing jobs, I have come across so many poor mountings, many of which were irreversible even by a paper conservator, using such poor adhesives as horse glue, white glue, wax, contact cement, spray adhesives, & old heat seal tissues, etc. Many of these stuck to such poor backings as cardboard, chipboard, wood pulp matboard, masonite, wood, & plywood. If a paper conservator can't remove the artwork without destroying it, then the only recourse is to re-frame & hope the piece does not deteriorate too rapidly.
There are many mounting options these days, with many new archival materials. Like mat boards though, these can run the gamut from bad to good, and I find some of them questionable. My favored mounting technique is to use "photo corners". These are hand made, folded, triangular corners made from cotton rag paper, that are placed on the corners of the artwork as in the illustration to the right. This covers the front & back of the corners, holds the artwork in place yet allows for expansion & contraction if applied just so, and prevents any glues or adhesives from touching the art. One can use archival linen wet mount tape over the top or a spot of conservation rice or wheat paste on the back to hold it in place, and it can have a v-slot cut on the face if close to the image so it does not show when matted. This is usually enough support for most art pieces except for perhaps very long horizontal works or oriental works of art on very thin rice paper.
On very long horizontal works of art that may sag in the middle due to weight, I often put a rectangular "clip" like arrangement of rice or rag paper in the center of the bottom edge similar to the illustration to the left. This is adhered to the backing, very close to the artwork, but not touching, with the top portion over the art, & "clamped" in place or held down by pressure from the matboard and glass. Occasionally, if the need arises or the situation calls for it, for example "floating" a piece of art work, then I will go with a traditional rice paper hinge. Rice paper hinges work great as they are thin, strong, yet will break or tear before the artwork in the case of a major jolt like a drop or falling off the wall. These are pasted to the artwork. Generally, as a matter of conservation principle, using adhesives on art work should be avoided at all costs, especially poor glues & tapes, or worse yet, volatile self stick tapes. But, if one must use an adhesive, it should be an acid-free, neutral, conservation rice or wheat paste, that is water soluble & reversible, i.e. completely removable with water, a gentle sable brush, without harming the artwork, or leaving any residue. I've seen some Alpha Cellulose & Methyl Cellulose pastes that look to be good, are said to be archival, but have not used them much. To the right is an illustration of a T-hinge & a straight hinge, but there are other variations. When using rice paper hinges, I try to leave a fair amount of rice paper in between paste spots to allow for lateral expansion, and I try to keep the spots as far as possible from an image if there are margins.
For over 25 years now I've done a lot of framing & matting for my brother, Roger Irwin, who is a wildlife photographer. Many of his photos can be rather large & many are printed on rather thin photo papers. Add to that the rapid & extreme temperature & humidity changes we have up here in northern Vermont, coupled with the fact that he does many outdoors exhibitions and art shows, and you have a recipe for a warping, rippling, bending, contorting photographic nightmare. Early on we had numerous complaints from customers about rippled photos. Encapsulating the photos, (see the Framing Page), slowed but did not solve the problem, and something needed to be done right away. So... I started fully mounting his photos & we haven't had a problem since. I use my cold mount vacuum pressure press, as I know that heat does not treat photos kindly. I use only 100% cotton rag museum board for mounting on. And I use an acid-free, neutral, pure vegetable starch adhesive paste that is non-toxic, non-wetting, & specifically made for the photo & framing industry. It is completely reversible in a water bath, but frankly, don't ever see the need for this as I consider the mounted package as one piece of artwork that will last a lifetime