I work in custom framing - dry mounting, while it has the obvious benefit of keeping the primary medium absolutely(ish) flat, is not ideal for ultimate preservation. I know dry mounting tissues usually state that they are archival/acid free, but a small part of me would personally doubt that. Additionally, unless the under/float mat is something other than white there is really no advantage over using the photograph's own white margin. We usually only dry mount when the customer specifically requests it or the photograph/whatever is impossible to keep flat. Also, damage is possible while dry mounting...unlikely, but possible.
It also presents a problem to potential buyers, who may like the image but would present it in another way. Sure, they could just trim off the excess mat, but most won't. They also then must crop since there is no longer any base medium to secure down. Most of the art dealers with whom I have dealt have simply suggested simple window matting as the presentation. If someone
really likes your work, they will spend (maybe
) the money to get it framed.
I don't have anything against dry mounting, as it affords some unique ways to present work. I've used it quite a few times, usually for books (but those were palladium prints with just a small strip of adhesive to just tack the top edge into the book, no need to worry about curling with that process).
I recommend these for mounting work behind window mats - no adhesive touches the work and it's absolutely reversible. Some double-sided tape to seal the mat to the backing board on which the art is mounted and you are set.
http://www.lineco.com/cart.php?m=product_list&c=1251&primary=1&parentId=&navTree[]=1257&navTree[]=2087&navTree[]=1251
There's my long-winded, caffeine-induced two-cents
. Ultimately, do what's best for your work and style.