Calipers measure veneer thickness. Frets are sawed by machine for accuracy. Necks are fitted one by one. The final product is played and sent to shipping or sent back for more work. (in the final assembly process, about 90 percent of the employee are musicians) By the time a Gibson guitar is ready to be shipped, it's passed through the hands of at least 30 crafts people and has spent four to six weeks on the shop floor. Despite such production precision , the company turns out about 300 guitars a day.