Homebrew PCBs

With mechanical etching you can mill and drill. Each bit will mill
3 to 4  4" X 6" boards. It is safer for students thats why the schools
use the machines. Every board is usable. Chemical etching in the hands
of a beginner is hit or miss. Milling is cheaper and faster in some
cases. TT is the way to go but it is not working for everybody.