People often want to incorporate LED’s in their t-shirts. However, stretch fabric doesn’t work well for circuits because it stretches while the conductive thread stays taught. You end up with broken thread and also some pretty nasty looking stitches, even if you use an invisible stitch. A good friend of mine approached me about incorporating an LED into her t-shirt, because it was highly appropriate — the logo on the shirt was for “The LightRoom”, a photography co-op. So, rather than lecturing my friend on the negatives of Jersey fabric, I decided to do a work-around. First, I tacked a Lilypad Arduino battery holder with switch on the label of the shirt behind the neck area, using regular non-conductive thread. That way there would be no stitches coming through the t-shirt fabric. (This works if you can handle labels, if not, you could stitch a piece of fabric label style on the collar and still place the battery holder there.)
Then, I fed some conductive thread in my needle and started with one of the positive petals on the battery holder, making sure to create multiple tight stitches like sewing a button. Moving to the fabric of the shirt itself, I connected to the bottom seam edge along the neckline with straight stitches, hiding in the seam until I reached the front side of the shirt. Remember that conductive thread can short with skin contact, so I kept the stitches between the seam and the t-shirt. Next, I picked up a piece of taupe satin seam binding, the kind often used in formal dresses to finish off a seam. I cut a length that would fit perfectly from the point on the neck to the spot on the logo where I would incorporate the LED. In this case, that spot would be above the letter “i”. I tacked the corners of the seam binding near the neck of the shirt with regular non-conductive thread.
After threading my needle with conductive thread, I made straight stitches joining onto the previous neckline stitching, moving directly into the satin seam binding. Keeping in mind the problem of stitches and skin, I made my stitching on the inside of the seam binding (not on the flaps), on the part that would be touching the t-shirt fabric. Once I reached the end, I stitched my LED in place at the positive side. Finishing up, I cut the thread and moved to the negative side of the LED. With new conductive thread, I stitched loops firmly in place to hold the LED, and then moved to the satin seam binding. Moving in parallel next to the previous stitching like a train track, I made another series of straight stitches leading back up to the neckline, being careful not to get stitches too close for fear of shorts. This time, instead of stitching on the lower seam on the neckline, I moved straight up into the upper seam. Like before, I made straight stitches under the edge, making sure to keep them between layers of fabric so they would not hit the skin. Following the same curve of the neckline, I made my way to the battery holder’s negative petal and stitched another series of tight loops to secure the petal in place. As with any electronic wearable project, I finished my knots with clear nail polish to prevent unraveling. As a finishing touch, I used regular non-conductive thread to stitch the flaps of the satin seam binding together, so they wouldn’t shift open under the shirt. So, in essence, this was like a mini bra strap inside the shirt that was only connected at the neckline and the LED.
Here’s the finished shirt powered on and my content friend!