I had been using the brown Catalog Envelopes with the metal pins and dry glue you have to moisten to make them stick. They disn't always stick my tongue got tired and the pins were so not needed. I would end up prying the fasteners off. I have been So Very Pleased with these Self-Sealing Catalog Envelopes. No mess no fussing no pull off strips to throw out. Nothing but press and stick. The sticking is Strong. The size of the envelope is just right for mailing out my pamphlets. You need to try these out you will be as happy as I am.