Storm window inserts for the arched, round and otherwise odd-shaped window.

Acrylic opens up all kinds of possibilities. It’s lightweight, more transparent than glass and can be made into just about any shape imaginable. Which is why people with odd-shaped windows, from arched windows to those resembling batwings, have sought us out to make them interior storms.

Often people with unusually-shaped windows didn’t think they were ever going to be able to block drafts on that funky little round window on the second-floor landing.

And then they found us.

Custom Geometry Production Sold Out for 2022

Due to high demand and inventory shortages, we have sold out of production spots for our special geometry windows for 2022. If you would like to get pricing information or be added to our waitlist, please contact us. Otherwise, we will update this page when production slots become available.

odd shaped windows

How do we make custom-shaped window inserts?

We ask people to make a template by tracing their window onto paper. Tyvek is the best, because it’s strong and light still shows through. On occasion, people will trace their odd-shaped windows onto tissue paper, but that’s prone to ripping. We don’t always need a template. Every window is different – we just try to keep the process as simple as possible. 

Here’s a picture of our Operations Manager Brianna, reviewing some window templates on our conference room floor.

odd shaped windows

After we trace the shape onto acrylic, we use a circular hand saw to cut it.

The circular saw cuts in small straight lines, kind of faceting it a little like a diamond. Then we sand that edge smooth, forming it into an arch or round, or the dips and peak of a window that resembles a fancy badge.  

This is a big departure from most of the inserts we make. For normal rectangular window inserts, we input measurements into a software program that tells our Computer Numeric Control (CNC) machine how to cut the acrylic.

Also, for normal, rectangular window inserts, we use a rigid ABS (Acrylonitrile Butadiene Styrene) plastic carrier with a silicone edge. But that won’t work for shapes that dip, peak, half-round and full circle!

For custom-shaped funky windows, we have to use pure silicone tubing all around the edge, like we used to for all inserts in the old days (which was just a few years ago!) It bends and molds nicely to the edge of round window inserts.


Some other shapes we can make inserts for:

  • Half-round.
  • Oval.
  • Gothic.
  • Eyebrow.
  • Bell-top.

Indow vs. other odd-shaped window solutions

It’s hard to find companies that make exterior or interior storms for odd-shaped windows. It’s labor-intensive to craft them of metal or wood, which makes them expensive. Plus, they’re hard to remove and put in.

“People are just generally surprised to find we do it at all,” said Brianna. “A lot of companies don’t. People tend to be surprised by how nicely they fit. They disappear into the frame.”

odd shaped windows

Have a funky window? We would love to see it! Share with us on social media on Facebook, Instagram or Twitter.

To see some great Indow customs, check out our Bowdoin case study.

Oh, and did we mention that these odd-shaped windows come in all our grade types, from Privacy to our UV-blocking Museum Grade? Check out our product pages to customize your order.

We’re happy to discuss your odd-shaped windows! Contact us here.