I found that chrome clip on the side of the road as part of a water damaged cardboard clipboard. It was unusable as-is so I decided to give it a new life with some plastic. This time I wanted to do something fun looking as opposed to the standard green, so I shredded up some black can carriers and white yogurt cup tops.
Of course it's all #2 HDPE, but I found that the black can carriers didn't really melt along with the others. They must have some additive, probably a stiffener, that makes them melt at a higher temp. The white yogurt top pieces did fine.
I also got to use one of my brass stamps sold by Precious Plastic itself, but since the letters are really small I also stamped in a "2" with my Harbor Freight stamp set to mark it as #2. Involving a torch and some patience, this is not a terribly quick process. However until I get a fancy mold with inserts, it's the best I've got.