Forbes, an electrical engineer, built his first video coat in 2009 after getting his hands on a collection of surplus LED displays. He transformed them into what he calls "the world's worst television," an all-red screen that weighed 50 pounds. He wanted to make a better, lighter version, and thanks to a side business selling homemade wristwatches, he had the spare cash. He laid an old overcoat out on a table, measured its dimensions, and guessed that he could fit it with enough LEDs to create a sharp 160-by-120-pixel display. Next he sorted through his gadget box and found a few flexible circuit boards. The flexibility was ideal for a wearable screen, but he wanted to have more pixels, so he built a prototype of a long, thin board with 30 rows of four LEDs each and shipped it to a circuit-board manufacturer to make 175 more.