These envelopes are strong enough to hold the thick contracts that we mail. Since we started using them we've had no complaints like we were getting that the envelopes were arriving torn in the mail.
I purchased these envelopes as an economical way to package t-shirts for mailing to our customers. They have been perfect. The price was low per envelope. They are tear-resistant which makes them tough enough to send bulkier items like our t-shirts. We use sticky mailing labels for our to and from sender and the envelope surface is great for these. Compared to the price of using the post office mailing envelopes we are saving a lot of money for each mailing. We have not received any complaints from our customers who have received t-shirts. An excellent economical purchase!
We have used Staples Brand products many times and have always been pleased. This particular envelope is definitely the exception. The issue is in the gummed tab. 1. The strips were not lined up alone the flap in a way that made it easy to pull off. 2. The glue are was a very small strip 3. The glue was not very sticky and since it was such a thin strip it required a lot of rubbing to adhere the flap to the envelope. I would rather pay a little extra on a better quality envelope in order to save time