Innovation-Blocking 3D Printing Patent on Producing Parts by Selective Sintering Expires

Cory Doctorow at Boing Boing had the story yesterday at Key 3D printing patent expired yesterday, writing:

"Yesterday marked the expiry of US Patent 5597589, "Apparatus for producing parts by selective sintering." This is one of the core patents in the 3D printing world -- the patent that allows 3D printer companies to charge more for fine nylon powder than Michelin-starred restaurants charge for filet mignon. The high cost of consumables in 3D printing has been a major barrier to innovation in the field -- selective laser sintering produces a fine finish that the patent-free fused deposition modeling technique used in Reprap-style printers can't match -- and now the brakes are coming off. "

This is another example of how patents do not foster innovation and progress, but achieve exactly the opposite.