Thought this may be of interest. Imagine using a paint pen to wire your layout, ect:
London-based Bare Conductive Ltd. makes electrically conductive paint called Bare Paint. The substance allows the painting of "liquid wiring" on any surface. Except for skin, you can apply its paint on walls and assorted surfaces to conduct electricity. Available in both paint cans or paint pens
Read more at: http://phys.org/news/2013-05-p...s-creatives.html#jCp