Gravity Falls’ Mabel Pines wears a light-up sweater frequently in the animated series, and Instructables user gurpleworlf decided to use LEDs to make her very own. She designed it to be a sturdy sweater, suitable for wearing more than once and for a few hours for cosplay puposes. She spent about 20 hours and $30 making the sweater; she found the sweater at a thrift store for $8. She crafted the letters and appliques from felt. Finally, she used LEDs. She said:
I weaved the lights through the sweater while I was wearing it. I thought this method was easier and wouldn’t disform the sweater with the wires. Since we are weaving the lights through the sweater, start from the shoulder and work your way down. Start on the inside (so the battery pack will be inside) and weave each light so it is on the outside. Continue spiraling down your arm making sure that each light is weaved and on the outside of the sweater. For each light, you’ll want to leave a bit of wire on the outside so it’ll have room to move without slipping through the fabric to the inside. Test your lights after every couple weaves to make sure they are all on the outside and ready to be glued. Bend the wire before the last light so it does not un-weave itself and slip inside the sweater.
Get complete details at Instructables.