I read that in Holland , researchers takes stereo macro pictures of Van Gogh paintings to extract the exact paint brush relief and 3D Rapid Prototyping Color print it with Canon Prisma RP machines. Well , if you cant imitate the different spectrums , thicknesses and transparency of used paints , its a useless attemp but IMHO in 30 years , they would overcome even that problem.

My main point , if you can create a 3D digital file of a carbon print either with stereo pictures or depending only creativity on the computer , you can print bw or color carbon or gravure prints even today with new RP machines in 3D.