How to Sew a Frown Window With Zippered Glass & Screen

The "frown" window is a favorite among experienced canvas workers for a reason: it’s incredibly practical. Unlike a standard "smiley" window that zips at the top, a frown-shaped zipper allows you to unzip only a small portion at the top to let heat escape while the lower glass continues to block the wind. Even better, this specific design features a dual-layer system. With independent zippers for the clear vinyl glass and the mesh screen, you can choose to have just the glass, just the screen, or a wide-open view.

One of the standout techniques in this video is the "shingled" construction. By overlapping the window material over the outside of the canvas, Seth demonstrates how to ensure water runs directly off the panel rather than leaking inside. This professional touch is essential for keeping your boat interior or patio furniture dry during a downpour. To achieve this look, Seth uses SewReady™ Seamstick Basting Tape to precisely position the layers before moving to the sewing machine.

The Secret to Smooth Curves. If you’ve ever struggled with zippers bunching up around a curve, you’ll love the "shrink-up stitch" technique featured in this tutorial. By slightly reducing the stitch length and sewing along the zipper tape before installation, you can pre-shrink the material so it lies perfectly flat against the arc of the window. No more bubbles or unsightly waves—just a crisp, clean finish every time.

Quality Supplies for Quality Results. To achieve the best results, we recommend using high-quality materials that withstand the elements. In the video, we showcase Strataglass, a pressed and polished clear vinyl known for its exceptional clarity and UV resistance. For the frame, Sattler® fabric remains the industry standard for durability and colorfastness.

When it comes to the heavy lifting, the Sailrite® Ultrafeed® Sewing Machine makes easy work of sewing through multiple layers of canvas, zipper tape, and thick window vinyl. We also utilize a 1-inch Binder Attachment to apply binding to the edges of the frown, creating a finished look that is as beautiful as it is functional.

This project is part of a special three-part series on frown window techniques. If you're looking for a simpler version, check out our tutorials on permanent screens with zippered glass or the basic single-zipper glass window.

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