This product is used for an organization that I am Secretary. It is used for mailing some payments and some correspondents. Available also for mass mailings that come up a couple times of the year. It does conceal unless head up to the light then you can see somewhat the contents.
It's a good thing I brought two boxes of these envelopes. The sealed edges of the envelope came apart on almost all of the envelopes I tested from one box. The other box had no flaws.I just could pass up the price. A box of 100 is usually around 9 bucks and these were [$] bucks for 500. In the furture I'll just pay the extra money to ensure that I get the quality I need.