I used a regular letter size envelope for one of my secondaries - one that had multiple pages (Minnesota). After I typed out my essay responses (only 2-3 pages -can't remember exactly - didn't want to too heavily sedated them with reading) - I had total of 6-7 pages. Folded and mailed with one of those lovely "Forever" stamps. Well the frigin' post office returned it saying I needed .17 cents more postage.😡 It was slightly over an ounce. So there added a couple of days delay in getting it out!