Envelopes are working just fine for our purposes. We haven't had the opportunity to test them in our inserter machine yet and that usually becomes a problem if the "glassene" windows are not sealed down all the way to their edges. Hopefully that won't be the case with these. We give them 4 stars.
This envelope does what it should do! Security Seals like a dream windows are in the right place time after time and the weight is perfect for our postage machine. No chewed up envelopes. It makes our job easy when we are mailing thousands of monthly statements! I highly recommend it.