Scaled up to 12" diameter to fit a 4mm BB. For this one I used 3/4" MDF and thin acrylic. I set everything to zero on the center of the piece, which made it easy to align for the back side. I’m still debating whether I’m going to try and paint it yet.
Painting MDF is a huge pain. You can try but it will look like shit and take lots of coats.
Colors other than black won’t look good, so if you do so I suggest you to paint it black.