That's a nice design.
Could you explain this process:
They will be engraved on aluminum and filled with black
I normally just use a carbide v-bit for the engraving, but I just received a bit that claims to be better. I'm going to try it and see if there are any notable differences.
For the color fill... I mask the alum and for automotive purposes and to match the color of the vehicle, I use the factory paint and clear supplied by the client. The dealers will sell a small jar of paint to match your code for a negligible fee. However, for this one, since it's black, it doesn't have to be a code match according to the owner. So, I have some black on hand.
I'll post a pic after it's engraved and cut, before color fill.