I have a small collection of underglaze transfers from Sanbao that I use to teach my students about this surface decoration technique. I have been able to store them in clear plastic sleeves in a 3 ring binder (and a larger portfolio case for the larger sizes) quite easily. I have not had any that went "bad"- and I have some that have been in the binder for 3 -4 years before they are used. (I can never predict what the "it" trend will be from year to year, LOL.) I hope to be able to have them create their own designs at some point... I have found these to be a great way to introduce students to the world of underglaze transfers.