Since I only needed a few I was pleased to find a relatively small package of these versatile classic envelopes. I’m sure I will find plenty of uses for the remaining.
My accountant got me using these for storage and mailing tax returns. Much better than using a letter envelope where you would need to precisely fold your document in thirds and squeeze it all in. I write large so plenty of room to write to and from addresses with leftover space for the post office to attach metered postage and registered mail stickers.