One of the hardest parts of running a paper shop is not keeping everything I find for myself! I have gotten better at this in the last few years and try to focus on just a few different ephemera collections.
Airmail envelopes are one of the first paper collections I started and probably my favorite. My collection consists of about 40 different airmail envelopes. There are certainly bigger collections out there, but I'm happy to add to mine slowly, but steadily. I don't collect any duplicates and usually find several airmail envelopes at a time, so I add one to my collection and put the others away for my shop.
My collection is pretty broad. I collect both new and vintage, used and unused, envelopes and postcards. I search for airmail envelopes pretty much anywhere I go. I often find old ones at antique shops, flea markets, and occasionally the thrift store. Most of my new ones come from office supply stores and, perhaps surprisingly, drug stores that have tiny stationery sections. Recently I have begun to seek out airmail envelopes when I'm traveling out of the country - again, usually at office supply stores. So far I have found some great ones while honeymooning in Paris and traveling in Mexico City.
I love the classic airmail border, but also look for envelopes with slightly different designs. I find these to be more common when traveling abroad. My brother brought me back the middle envelope from his time in Central America.
A few others from my collection - both classic and a little unusual. This is one of the only "Business Reply Mail" envelopes I've come upon with an airmail design.
I am really drawn to those with unusual colors. It is a bit tough to see, but the top envelope has a pale mint green background. The blue bottom two are United Nations airmail envelopes. When I bought them I didn't know anything about the United Nations postal system that I shared with you guys recently.
Without question, my absolute favorites are these (addresses removed for privacy) from my late grandmother. Last year my parents gave me a vintage wood box for Christmas. Inside were several old letters that once belonged to my grandmother sent from family in Germany. Some of the envelopes are torn because she kept them for the memories, not to be pretty ephemera. But they are still my favorite gift from last Christmas and my favorite envelopes in my airmail collection.