So we had 3 layers of fabric: two normal pieces and one of conductive fabric. Then we were sewing lines with conductive thread on the normal fabric. We added two lines of conductive fabric to the first layer to spread the voltage over the entire first layer. The conductive thread had 4,5 Volt running through. Then we added one layer of normal fabric to separate the first and third layer. Finally we added the conductive fabric to the bottom. Now the batterie got connected to the first and third layer, giving ground to the bottom layer (the conductive fabric) and power to the top layer (the conductive thread spreading power of the normal fabric). Now you could take LEDs and stick them through all layers in order to connect the plus “leg” of the LED with the top layer, at the same time connecting the minus “leg” of the LED with ground via the bottom layer. VOILA!
