These pockets are made of heavy duty plastic and seem to hold up nice. the zipper is just like those sip-lock bags that have the little tab that moves back and forth.
I bought some Kaisercraft clear stamps - which they package in one of these pockets - this brought me to looking up their storage products and I found their notebooks and empty pockets.
I feel like these have been the perfect answer to my clear stamp organization issues. These MEDIUM size fit the Inkadinkado sets or two of the american crafts small sets of stamps perfectly. The LARGE (7" x 9.5") pockets are also great.
The only reason I gave it four stars was because I'm afraid the little zipper tab might come off, but sp far, they're holding up!
This fits my Inkadindado clear sheets perfectly.