Yep, ATG 969 is the stuff. Use if you don't intend, ever, to make a mistake and try to peel it off. It will take with it whatever you put it on. But...make sure it's "fresh". Found some in the "new-old" shop, don't know how old it was, but it had turned yellow, petrified, and not very sticky. Only one roll though, I've never seen that before. Makes me wonder if it does that over the years on the framing projects it's stuck to. Never thought of that before.
So...I agree with Jim Miller, and in the future, when using 969 in my shadow box liners, I will back it up with a few drops of white glue, Corner Weld, perhaps??
And I'm with Ron about the acid-free stuff. Doesn't stick very well at all.
Acid-free ATG tape... seems like an oxymoron to me. Except for maybe attaching mats together in an archival treatment, no "vapors"? Am I correct in this assumption?
Ron, with all this new technology in framing, I also feel like I'm forgetting all I ever knew about framing...Mad Cow Disease also? Oldheimers? Or just plain new technology and sales reps telling us oldtimers that what's worked for us for years is bunk now? (Somehow, I think not, and Paul Fredericks might agree with me...RIGHT PAUL??)