There are millions of U.S. patents now in the public domain, which means they are free for anyone to use. Martin Galese, a New York lawyer, found the archives to be the perfect inspiration for 3D printing designs. A New York Times article says he has made a hat comb, stove pipe screw, pot scraper and more. The 3D designs are available on his blog and Thingiverse. “You’re holding the 19th century by way of something that was produced in the 21st century,” Galese said.