Very good product. The envelopes are nice and strong and sturdy. You can not see through the envelopes and I love the fact that I do not have to lick the envelope to seal it.The envelope has glue already on it and is covered with some pull away paper. Once you have the envelope ready with everything inside of it that you want to mail you just pull the strip of paper off of the flap of the envelope that has the glue under the paper and just put it together as if you had just licked the envelope! That was easy!