Hello everyone! I have several signed items I’d like to store in acid free binder sleeves. For 8x10 photographs someone suggested the Ultra Pro 1-Pocket Platinum Page with 8-1/2" X 11" Pocket together with Ultrapro magazine size boards as a backing. Or would it be better to buy the UltraPro sleeves that were made especially for 8x10 photos without the backing? 

I also have some signed 4x6 index cards. Do you use a backing for them too?

And the same question for handwritten letters. Can

I use the same backing for this? 

Is anyone familiar with the binder sleeves of Archival Method? They have an option with the backing already included but the backing is less thick (14 points against 24 points for Ultrapro). Is 14 points thick

enough?

https://www.archivalmethods.com/product/pocket-pages-with-inserts?zCountry=BE

I plan to put everything in an archival box.

Many thanks for all your help!