Tired of every printed circuit board you etch coming out brown? Take a page out of [Dane's] book and dye your PCB to just about any color you want. One hour submerged in a 200 degree bath of Rit dye turned his brown FR4 substrate to the desired dark green. We give him points for being dangerous enough to use a broken bottle as a vessel, yet wearing eye protection at the same time.
We never really thought of doing this, but it’s pretty interesting that it works. We’ve stained the substrate when removing etch resist so this should have been obvious, but wasn’t.