a review of adhesives used by actual scrappers...and a lot more!
A review is coming soon, but here is some information from 3M's website:
according to 3M's own website and data sheets, only the Scotch ATG Adhesive Transfer Tape Acid Free 908 Gold is archvially safe-it is photo safe in accordance with both Black and White Photographic Activity Tests and Color Photographic Activity Tests (per ANSI IT9.16)
Tape 908 has a pH between 7.0 and 8.5
the other tapes are made with glues that 3M lists as not archivally safe.