Daily Caller 
Dec 11, 2012
New York Democratic Rep. Steve Israel is calling for legislation to renew the federal ban on plastic guns, according to his official congressional website.
“Recent reports have pointed to the new possibility of building guns at home using a 3-D printer,” Israel’s website states.  “Right now, plastic guns are illegal under the Undetectable Firearms Act, but this law is set to expire next year.”
3-D printers, which have been available since the 1980s, take two-dimensional plans and convert them to three-dimensional objects, which are then usually made from plastic.
Homemade plastic firearms are difficult for airport X-ray machines to detect. They also cannot be registered or traced, because they lack identification numbers.