Printed Circuit Boards, or PCBs, are the panels on which the electronic circuit is placed. Older boards often reveal hand-drawn traces, which are much more fluid in design. With computerized PCB design, those lines straightened out. Most PCBs are made from FR4 (glass fiber and epoxy)[^fiberglass].
[^fiberglass]: Fiberglass is very strong, but can be sawn through. When sawing, make sure you wear the right protection, microfibers can end up anywhere.
The copper tracks on a PCB are usually covered with a green protective layer, known as solder mask. Sand this off and to expose the copper underneath, ready to solder onto again.
Most boards are labeled. They can include a date, information about connections, component numbering[^component-numbering], and sometimes even their their values [^monotron].
Not all PCBs follow the industrial template. Artists and other tinkerers have come up with alternatives: the paper circuits of Ciat-Lonbarde, or Dirty Electronics’ boards made from wood and nails. These kinds of formats offer a more punk-diy way of publishing projects, where the format is not set in stone. Paper can be cut, nails can be moved, inviting a maker to explore the circuit more then just soldering a pre-compiled kit.[@blasserStoresMall2015][@richardsDIYElectronicMusic2013] For our circuits, these approaches are ideal—still flexible, still open to change.
