Though materials used with home 3D printers are generally limited to plastic products, industrial printers like Sculpteo's can churn out such premium materials as sterling silver. The company sells, for example, a signet ring available in a selection of three patterns: an anchor, a skull and crossbones, and what looks like an alien cartoon figure. Picking one of those patterns counts as customization, which will cost you a hefty $350. 

 

If you like whimsical jewelry, there is no shortage on crafts site Etsy. Fanciful sterling-silver items include a Green Lantern ring for $54.99, a Pac-Man ring for $67 and a pair of "Doctor Who" wedding rings ("Time Lord" and "Companion") for $90. You could walk away with a handful of jewelry in exchange for that one printed signet.