Step 1: Materials
Wooden base (square)
String (I used hemp)
Something to mix your paint in
Painter's or masking tape
Something round (not spherical) to use as a template. The diameter should be able 1/2 the size of the side of your wooden base.
Exacto knife or razor
Everything on this list (except the power drill) is available at your local craft store.
I used water based paints for the companion cube. I would not recommend using hemp for the string. I would recommend using something with a much more uniform texture.
Step 2: Paint the Base of the Companion Cube
Step 3: Make the Line Detailing
Again, you must mix the paint. For the pink, I mixed 3 parts white to 1 part red. After mixing the pink paint, coat one side of the string with the pink paint. Place the string on the companion cube, ensuring that you are placing the string over the mark that you just made. If the detailing does not come out exactly the way you want it, touch it up with a smaller brush of pink paint. If you REALLY hate it, it's easy to start over at this point. Just coat the whole cube in the same dark gray again and start this step over.
Step 4: Center Circle
Mix a lighter grey color for the edges and center. Paint inside the circle and let this dry. Remove the tape.
I found after the first few pieces that masking tape works better than blue painter's tape.
Step 5: Outside Detailing
For the corners, tape off the area approximately half an inch outside of the detailing you just painted. Again, follow the circle, this time leaving approximately half an inch between the circle and the corners. When dry, peel off the excess tape.