I have an Epson ET-3750. Feeding envelopes is hard as they can only feed about 10 at a time as they are high from the flap in the feeder. The proper size is 6 3/4 not 6. I was concerned when I ordered but the box said 6 3/4
We would love to continue to use Staples brand gummed envelopes but since they do not stick well we are considering an alternate. Unless you can remedy the issue of inadequate sealing.