Tim,

I've seen red chalk lines still on old timbers. Every time, I get really excited for some reason.

You can still get carpenters chalk from Dixon. It' a slightly convex cone shape, about 2" diameter base. We use it to mark reference, or designate timbers or any other temporary working mark or label. I've heard it was rubbed onto strings for lining work.



I've heard of the charcoal thing, but don't know any hard evidence. The same for juice from a poke berry. I do know they stain your hand.

Interesting question...