Envelope Basics: Windows

By Jerry Prebelski

"Envelope Basics: Windows" is part of an occasional series titled "Envelope Basics" that provides an in-depth look at all-things envelopes - elements, measurements, ordering tips and more*.

Envelope windows are a wonderful way to highlight something important. They can be used to show recipient or return addresses, showcase a product or promotion, or even call attention to the envelope itself when a custom window shape is featured.

If you’re “window shopping” for your next direct mail campaign and windows are an option, congratulations! You’ve come to the right place. Set your window envelope up for success by familiarizing yourself with these basics first.

Window Placement

At a minimum, windows should be placed 1/2" from the side and the bottom of the face of the envelope to ensure adequate room for patch adhesive. Standard placement is 7/8" from left and 1/2" or 5/8" from bottom. Standard envelope window size is considered 1 1/8" x 4 1/2" or 1 1/8" x 4 3/4". For details on how to measure a window envelope, see our blog post that features step-by-step instructions.

Window Patches: Open or Closed

Envelope window openings are either open-face or closed-face. Open-face, also called open panel, window openings are highly susceptible to tears and snags in the inserting process and postal steam.

Closed-face window panels have a window patch that is sealed to the envelope with Tension's Solid Seal® high-performance gum adhesive. The window patches are available in a variety of materials:

  • Polystyrene – A translucent, petroleum-based material. The most common type of polystyrene patch is filmview. It is the most cost-effective, can be recycled and is postal approved. Trycite is another type of polystyrene window patch that is more brittle, prone to scratches, highly reflective and more expensive.
  • Glassine – A milky, cloudy patch material made from wood products. It is susceptible to moisture and humidity.

Custom Window Envelopes

Custom windows give you limitless ways to add creative freedom and fun into your mailpiece. Make a statement with your policy mail with a large window shape on a large 9x12 open side booklet envelope. Create a shape that reflects your organization, such as our popular dog-bone shaped window. Work in the element of surprise with multiple windows or a window on the back (non-insertable side) of the envelope. Or, include some color and a call to action around the window to mimic the look of a sticky note direct mail envelope.

Let your promotions (and creative side) shine through with envelope windows. Contact us today to talk about which options are right for your next campaign.

*This blog is intended for informational purposes only. Exact envelope specifications should be discussed in detail with your Sales Representative.