I do not use any of the flat rate boxes for the most part all my customers buy things a lot of them just this week I packed two orders that were over 200 items. and the flat rates never work out. plus by living in a camper I don't have room to store them. I also do not use envelopes the 3 times I tried, the items were damaged going through the machines at the post office and I have never in six years had a customer that was so set on the flat rate boxes. I am not being difficult I am just old and set in my ways