How to Make Insulated Blackout Window Panels (tutorial)

It's summer, and that means people are getting their vans road ready for the fall climbing season! One of our additions has been blackout window coverings for those times you need to stealth camp, that also didn't look like we pasted tin foil in our windows.

Before: Classy light-resistant curtains
Insulated Blackout Window Panels tutorial

After: Custom-fit blackout panels
Insulated Blackout Window Panels tutorial

You'll need:

**Note: We have a Ford Transit, which doesn't have metal trim around the window. I would have preferred to make the blackout insulation bigger than the window and mount it with magnets. Instead, I form-fitted the insulation to fit in the small slit between the glass and the black plastic border on the inside. I made the panels to fit in this groove to be lightproof.
Insulated Blackout Window Panels tutorial

Measure the window's largest dimensions.
Insulated Blackout Window Panels tutorial

Cut insulation to the rough rectangular outline.
Insulated Blackout Window Panels tutorial

Fit it in the window and use a sharpie to mark how much to trim. 75% of my time was spent here getting a perfect fit without cutting too much. It's like that tale of the boy who wants to make a perfect heart for his valentine, makes a hundred cuts, and ends up with a minuscule size heart. Anyways, take your time and don't cut too much.

Insulated Blackout Window Panels tutorial Insulated Blackout Window Panels tutorial

Cut felt much larger than the insulation. Generously cover both sides with the spray adhesive. You want a good thick layer. One can was good for about 1.5 windows.
Insulated Blackout Window Panels tutorial

Press the insulation and felt together to make sure that every inch is adhered.
Insulated Blackout Window Panels tutorial

After the first side, cut the felt to size.
Insulated Blackout Window Panels tutorial

Glue and press other side. Note that waiting to cut the felt to size after this step is really hard since with the felt overhanging both sides, you can't see where exactly the insulation stops.
Insulated Blackout Window Panels tutorial

Now apply the bias tape for a nice edge finish. Bias tape is widely used in crafts and sewing and there's many tutorials online. It's also the same way you bind a quilt! You want 1/2" double fold bias tape. First open the bias tape so a single layer lines up with the edge.
Insulated Blackout Window Panels tutorial

Sew along the crease, starting in a straight section (makes the next steps to join the ends easier).
Insulated Blackout Window Panels tutorial

Stop with like a 10-12" gap from where you started.
Insulated Blackout Window Panels tutorial

To get a form fit, you'll need to cut the bias tape and make a seam. Line the two ends of the bias tape up. Mark where the two exactly meet (the right line), and mark 1/2" beyond that so they overlap (the left line). Cut the left line.
Insulated Blackout Window Panels tutorial

I missed a photo of the next step, but you want to fold the very end of the right side over ~1/4" and iron it flat to make a nice edge (rather than a raw edge), then lay the left side on top of it, then stitch the whole thing down to finish, like this tutorial "Joining Two Ends" section.

Flip the bias tape around. The center crease will align perfectly with the edge of the insulation.
Insulated Blackout Window Panels tutorial

With the other side on top, sew down the bias tape close to the edge. It doesn't matter whether you catch the bottom side's bias tape edge since you already sewed it down.
Insulated Blackout Window Panels tutorial Insulated Blackout Window Panels tutorial

[Sidenote: You could put the bias tape around the insulation and sew once to catch the top and bottom, but in practice it's nearly impossible to be this close to the edge with a straight seam and catch both sides since you can't see the bottom.]

I added a couple more rows to flatten the edges so they shove into the narrow grooves easier.
Insulated Blackout Window Panels tutorial

Yay!
Insulated Blackout Window Panels tutorial

For the front side windows and front dash window, I covered only one side with felt so we have the option of reflective foil in extreme heat or blackout for stealth mode.
Insulated Blackout Window Panels tutorial