Gable, any detail on how they would have snapped those lines? In the description it sounds a bit slobbery, splattery. Has anyone seen antique line baths that would point in that direction?
Here is a link to a description of using water and venetian red (ferric oxide) from Hodgson's
Light and Heavy Timber Framing Made Easy. The entire book is available for download as a pdf on google books as it is public domain.
http://books.google.com/books?id=kkk1AAAAMAAJ&printsec=frontcover&dq=light+and+heavy+timber+framing+made+easy#PPA172,M1
