Our Certified 9x12 Envelopes are the best quality that you will find. Their durabilty make automated inserting certified mail® easier than ever. This envelope does not have an inside tint. A full front window eliminates the need to print your return address on the envelope and cut out having to worry about aligning addresses with windows. Again, these Certified Mail® envelopes eliminate matching, maintain optimal quality control and are compatible with high volume machines.