There is in the Dollar Store an item labeled as "flow-rite" Gel Pens. They are just 4 inch long pens with the regular ball point tip andbarrel. The colors are red, blue purple, green, gold and silver. I find the silver pen great for filling in the color for tiny goggles and the vision ports on the Sherman cupola. Just write in the space defined by the raised rim. For the gold pen draw the gold on the casing of a belt of MG ammo. In both instances the edge of the paint is sharp and precise. It beats painting with a brush. I haven't found a use for the other colors yet. I think they will be great for drawing trim lines on car models.