With the aggressive cost reductions for 3-D printing made available by the open-source self-replicating
rapid prototypers (RepRaps) the economic advantage of custom distributed manufacturing has become
substantial. In addition, the number of free designs is growing exponentially and the development and
commercialization of the recyclebot (plastic extruders that fabricate 3-D printing filament from recycled
or virgin materials) have greatly improved the material selection available for prosumer 3-D printer
operators. These trends indicate that more individuals will manufacturer their own polymer products,
however, there is a risk that an even larger fraction of polymer waste will not be recycled because it
has not been coded. The current limited resin identification code available in the U.S. similarly restricts
closing the loop on less popular polymers, which could hamper the environmental impact benefits of
distributed manufacturing. This paper provides a solution for this challenge by (1) developing a recycling
code model based off of the resin identification codes developed in China that is capable of expansion as
more complex 3-D printing materials are introduced, (2) creating OpenSCAD scripts based on (1) to be
used to print resin identification codes into products, (3) demonstrating the use of this functionality in
a selection of products and polymer materials, and (4) outlining the software and policy tools necessary
to make this application possible for widespread adoption. Overall the results showed that a far larger
resin code identification system can be adopted in the U.S. to expand distributed recycling of polymers
and manufacturing of plastic-based 3-D printed products.