Window Envelopes Continued

Crystal Clear/See Clear^®

Our "See Clear" material is a crystal clear polystyrene film. It is dimensionally stable, and moisture resistant, but also shares the "EZC" limitations regarding exposure to heat and recyclability.

Glassine

"Glassine" is the third window patch material, and one which has received much more attention recently as the environmentally friendly alternative to the plastic patches. Glassine is a paper product, and is therefore recyclable and reputable. It is not as clear as polystyrene, but is still readable. However, glassine is affected by humidity and the windows can pucker and become wavy, sometimes to the point of causing character distortion on the Optical Character Readers used by the Post Office to sort mailings. Heavier weight glassine has proven to be more stable than lighter weight glassine. National Envelope now uses the heavier weight glassine exclusively. This does not eliminate the risks described above, but does minimize them. Of course, proper handling and storage should also reduce the effects of high humidity on glassine.

Canadian Window Envelopes

Tinted Envelopes

Tints printed on the inside of the envelope are generally used to increase opacity for security purposes. Tint designs are often used in direct mail, not only for opacity, but as an enhancer to the message they carry.

Inside tints are available in stocked envelope sizes. Custom tints in different colors and patterns can be enhanced with company logos or slogans and are available on custom orders.