I like that these don't have a metal clasp as they go through the postal machines more easily without metal. Unfortunately the gummed closure isn't strong. One of them came open in the mail and arrived to my customer open and empty. The contents had slid out and were lost.
Needed envelopes that were a little bigger than the standard brown envelopes.. This is the only place for a good price that had the slightly bigger ones.
In our small office we often find that 9x12 envelopes are too small for the paperwork we need to mail to clients and 10x13 envelopes are too big. I had never seen these 9 1/2 x 12 1/2 envelopes before...they are perfect for us.
These kraft envelopes are very sturdy and well made. The adhesive on the flap is good and sticks well (although for mailing I always back a flap up with some tape). The center seam of the envelope does not seem like it will open up as with some cheaper envelopes. I am even comfortable enough to mail a well-wrapped lightweight book in these envelopes.