Technicaly wooden frames are not "archival", but then again many excepted forms of presentation are not exactly archival either. For example - putting your prints in metal frames and keeping then on display 24/7, 365 days a year is also considered to be an "archival" no-no. It is generally advised that you rotate prints in and out of display to extend their life, as enviromental polutation is now considered to be the greatest enemy to preservation. There are some standards (that for the average person/photographer) are almost impossiable to meet when it comes to exacting preservation standards of your photographic prints. But if you do suffer from "archival paranoia" then your photographs should be stored away in a light tight vault at proper temp and humidity. If you are a photographer (not a collector) your first archival concern should be the proper storage of your negatives. We are always surprised to see how many experienced photographers store and handle their negatives completely improperly. At our gallery all work is displayed in wooden frames (primarly for the reasons stated by Les McLean) and under UV plexi, but the work is only kept in these frames for the length of the exhibit and then removed and put in proper storage. It should be remembered that the archival standards that most of us know or have read of are based on the idea of long term inactive preservation storage (as opposed to an active archive in which the negatives and prints are in continuous use)