Amazing and sturdy! I am very pleased with them!
Here is a quality mailing envelope that I have bought more than once for selling books on Amazon. To save money, I wrap the book I am sending in bubble wrap, then place it inside one of these envelopes- inexpensive padded envelope! These mailing envelopes are durable enough to mail this way and you save lots of $$.
I run a small business in Indianapolis and these are perfect! The envelopes are bigger than standard paper and can hold often a quite a bit. I use these with my employees who weekly scan all receipts of money the business spends and makes. We weekly use up an entire accordion binder full of paper, scan it, and file it all in ONE envelope. Love 'em! They've never ripped or broken in any place. Our old envelopes were also 10x13 but we constantly had to use two, sometimes three envelopes for the same amount of paper we use now. I will reorder again!