Glassine semi-transparent envelopes, are the ideal storage solution for stamp collectors. Glassines are also recommended for the storage of negatives and plates from electron microscopes, and temporary storage of seeds. Also used in scrap booking, crafts and wedding and party invitations. The uses for glassines is endless. Numbers and identifying information can be written on these envelopes. Adhesive labels also adhere nicely. Size is 4 1/4 inches by 2 1/2 inches with the opening on the long side.