Dear Angie,
Here is some information I found online that might be of help:
http://www.wm-arts.com/Information1/certificate_of_authencity.htmFor me personally, I believe my signature on the back proves the authenticity of my work, but if someone requests a certificate I would be happy to create one. To me, though, the artwork should stand on its own, regardless of who's name is backing (i.e., is it valued for its content and aestheticism or is it because the person who created it is more famous). I don't think I've reached the point where I need to even worry about that yet as I'm definitely not famous.
As far as open and limited edition prints, this is my thought behind it. These are not prints that are created by the artist (as in a printmaker, back when the prints would go down in quality each time they were hand printed, hence one of the reasons behind limiting the number), they are reproductions of your work that are mass-produced by a machine. Of course, the less you produce, the more valuable (presumably) each piece will be, but then again most of us haven't reached a point in our careers where our work is pulling in millions so the difference is slight (in my opinion). If you do a limited edition, you also have to be extremely careful to print only as many as you say you will, otherwise you're losing the trust of your clients. Here is what it comes down to for me (for the artist, open edition prints provide more flexibility for the future, for the collector limited printing is a better investment).
Here is some information I found regarding open and limited edition prints:
http://www.ehow.com/about_6621099_definition-open-edition-print.htmlhttp://blog.pencilplace.com/2010/01/reproducing-two-dimensional-art-open-edition-prints-vs-limited-e...Hope this is helpful, I will look forward to hearing what others think about it ;o)
hugs,
brienna