Wether you’re etching or #CNC #milling your own #PCBs, the copper layer on the substrate will eventually begin to oxidize and rust. The best way to prolong the life of your PCBs is to give them a protective coating. This is where #PCB Solder Masks come into play! Check out the tutorial for list of parts and supplies: https://learn.adafruit.com/how-to-solder-mask-pcbs https://youtu.be/wvU2yyfH-XE #DIY #Electronics #Adafruit | Adafruit Industries