+so you might want to pick up an extra.
+
+Many keycap sets (not the one linked above) are "sculpted", meaning
+that keys that go in different rows have a different shape. While you
+can use these for an Atreus, it's unlikely you'll find a set with the
+correct number for each row, so it's more wasteful.
+
+** Circuit Board
+
+The =atreus.rkt= program calculates switch and diode positions based
+on row/column counts, spacing, and rotation factors, and emits a
+=atreus.kicad_pcb= file. The board outline and traces are done by hand
+and are stored in the =header.rktd= and =traces.rktd= files
+respectively. The =atreus.kicad_pcb= file can be imported into [[http://kicad.org][Kicad]]
+which can export Gerber files suitable for fabrication. A copy of the
+Kicad PCB file is included in the repository if you don't want to
+recompile it using Racket. Recompiling is only required if you want to
+make changes to the procedurally-generated portions of the board.
+
+Unfortunately most PCB fabricators require a minimum order of 10 or
+so, making this impractical for one-offs. The PCB is not required, so
+for one-off boards it's usually more sensible to stick with a [[http://atreus.technomancy.us/assembly-hand-wired.pdf][hand-wired build]] instead.