Step 1: Supplies and Tools
Altoids tin - whatever style you prefer, but my Arduino fits perfectly in the standard size so that's what I used
Masking tape - to eliminate overspray on the outside of the tin
Paper towel - for cleaning
PlastiDip - this is the good stuff, a "multi-purpose rubber coating" made by Performix
For tools, you'll need these:
Hands - for doing things
X-Acto knife - for cutting away excess rubber after drying
Small flathead screwdriver - for taking apart the Altoids tin
Step 2: Prep
After that, you'll want to separate the top of the tin from the bottom, as this will make masking and spraying easier. Take a small flathead screwdriver and gently pry the hinges away the lid can be lifted out.
Now it's time to mask off the two parts of the tin. Using masking tape, cover up the entire outside of the tin up to the curled edge.