Above is a peak at the progression from design to finished product.

High level steps are:

Trace/design image in SolidWorks Import STL file into PartWorks 3D and mill into a piece of wax using ShopBot Use wax to make an Oomo mold Use Smoothcast liquid plastic to make the door decoration Spray paint/hand paint

I played around with my doorknob and determined that it most definitely could not be taken apart without cutting straight through the piece. Thus, I knew I'd have to mold two parts that could fit around the knob. I started off by making my model in SolidWorks. I imported an image of the character and traced it, then extruded in varying degrees.

Note: To trace an image in SolidWorks, create a new sketch and then import an image of your choice via Tools->Sketch Tools->Sketch Picture. You can then use the standard drawing tools to sketch over the image.

Alternatively, you can just use my Solidworks file (AUGUST 2016 UPDATED LINK: https://www.dropbox.com/s/w4diswk5mksqgdl/doorknob.SLDPRT?dl=0) , if you give me credit :)

I hoped to add more texture than Solidworks allowed, so also played around with Autodesk's Mudbox (first image above), a truly remarkable program that lets you push and pull meshes around like a block of clay! Although I had a lot of fun playing around, I worried that the design might come out looking messy, and so ultimately opted to print the flat version and save some more subtle work with Mudbox for another time. [Pro tip: if you'd like to use Mudbox with a SolidWorks file- you'll need to use Meshlab to convert from STL to OBJ formats).