Polycaprolactone (PCL) is a hand-moldable plastic that's useful for hobbyists and prototyping. It's sold under various names like Polymorph, Shapelock, Instamorph, TechTack, etc.

PCL sticks to most plastics. Things it doesn't stick to:

Fabricating techniques:

Shaping techniques:


Webpages that discuss techniques: [1] [2] [3] [4] [5]