I agree with Vaughn. The mat is integral to the work. I fully understand that museums like the print to be able to be separated from the mount board, but when I wrote the article on ArtCare board, which iconsisted mostly of an interview with the inventor, I discovered that dry mounting adds a layer of protection to the work from environmental pre-acidic gases, making a dry mounted print more archival than one that is only hinged. The pictures in my article show that. You will see that those who think not dry mounting is more archival are simply wrong.
I think that will get you there. If not, just click on the link on the left to "Article by Michael A. Smith."
I have always signed my prints on the mount board. If one signs on the back there is always the danger, especially is one has a forceful hand, of having the signature show through to the print. And leaving a white border around the print, and signing there, is problematic for a number of reasons. 1) Later some conservator might cut off that border. But more importantly 2) If the white border is ever seen, particularly with a print made on glossy paper, it will be the whitest thing visible and will draw the eye and thereby be a major distraction--and it will greatly diminish the experience of the work. One can get around that by having an overmat go right to the edge of the print but if one uses the entire space of the picture surface (as I believe any serious photographer ought to do) then if the overmat covers the picture by even a millimeter, or less, spatial relationships of things at the edges are destroyed and the picture is no longer the same picture. Having an overmat cover part of the picture surface is like taking some notes out of a piece of music or cutting some words out of a poem. The problem with pre-cut overmats--ones made to a standard size, is that they are made so that they usually cover overlap the edges of the print. I use overmats that leave borders around the print of about 3/8 on top and sides and 1/2 inch on the bottom, which leaves a little extra room for the signature. And mounting prints that way--with a larger overmat than the print, makes is very easy. No measuring is required. One positions the print visually.
A photographer was here recently and suggested we make a video about how we mount prints. We'll do so after we return from Paris Photo and Art Basel Miami Beach. We are giving a talk at the Art School at the Boca Raton Museum on December 10. You are all invited. It's free. Our "Vision" workshop follows the next day. Spaces still available, I think.
Weston, Adams, etc. all signed their prints on the mount. As I have said on many occasions If a way of doing things was good enough for Edward Weston, it is good enough for me."
Michael A. Smith