For the hobbyist/maker crowd.
Bare Pens are a great electronics prototyping tool for makers/hobbyists of all ages. Nontoxic and water-soluble, they can be used without gloves or mask. Once applied the paint dries quickly at room temperature and can be removed with soap and water. Paint is black in color and can be over-painted with any material compatible with a water-based paint.
Dries in 10-15min at room temperature
Can be sealed, and layered, using acrylic paint or spray varnish
Water soluble: remove it with soap and water
Works great for PCB repair, or used with conductive thread and e-textiles
Surface resistivity of approximately 55 ohms/square, at a layer thickness of 50 microns