Thanks, UltraPro I think is who makes all the sleeves from my card collecting days.
The ones in the link will definitely work for my lithographs, but I'm not sure on my good prints (Cook & Becker giclees). Maybe I'm overly concerned, but when it doesnt specifically state "acid-free" or "archival-grade" I worry about the sleeve damaging the print over the years. I do keep them in either my firesafe (in the tubes) or under my guest room bed, so no light hits them either way.
As for size, the 24x36 is the entire size. I had to do an Excel file to list all my prints and have a column with the border add-on for each
So if I did use them for my good prints, all but 2 would fit that 29x43.