The stickiness of the tape, combined with the silicone’s resistance to most adhesives, has a side-effect that’s now quite useful: it has a weak hold like a Post-It® Note, making it possible to reposition the strip as we work through this next sequence.
Identify the LEFT TEMPLE of the hat and press the strip against the carpet tape at the BOTTOM (closest to the hat’s brim) with the WIRES toward the BACK of the hat and the STRIP toward the FRONT.
(In this photo, the front of the hat faces left.)
Once they’re reasonably aligned, make a mark with a Sharpie pen and count the number of NeoPixels between the marks. You’ll need this number later when we program the Arduino.
The rows of strip don’t have to butt right up against each other. I tried to leave a couple millimeters spacing. The Post-It®-like hold of the tape makes it easy to back up and try again repeatedly.
It’s bothersome up close, but at any reasonable distance nobody will notice. Sometimes referred to as the “ten foot rule” in cosplay.
Also, it’s unlikely that the start and end of the strip will be aligned. This too is okay, we’ll simply turn the sleeve to put the most pixels at the front.
My hat has seven rows of NeoPixels in the front, six in the back. Part of the text will be cut off in back, but don’t worry about this…it still gets peoples’ attention, and they’ll come around the front to ask questions about your hat!
If your hat has seven rows in front, one of these joints (at the 2 meter mark along the strip) will now be in the very center. You can use this to align the sleeve with the hat, so it’s facing directly forward.