Woodblock printing is one of the oldest mediums used by 'illustrators' in that it could be mass produced. Almost as soon as the printing press was invented, woodblock illustrations found their way into the text as well, especially in religious manuscripts like this illustration by Albrecht Durer. Outside the Europe though, woodblocks had been in use for far longer, with recorded examples in China from at least 220 b.c. and even a few examples from ancient Egypt.
The most famous examples of woodblock printing are the Japanese Ukiyo-e prints such as those by Utagawa Hiroshige.
Some contemporary artists that use woodblock printing are Tom Killion, Ralph Kiggell and the Brazilian folk artist José Borges.
Some interesting qualities of traditional woodblock prints are the texture the paint leaves on the paper surface, which can be effected by how much ink is used, paper thickness and tooth, how much pressure is applied, and other factors. Edges are usually bold, and their edges are different depending on what material they are carved into, whether it be linoleum block or actual wood. Even the grain direction of the wood has a bearing on edge quality: finer cuts can be made on an end-grain section of wood (sometimes called wood engraving) than can be on a normal plank. Different gouge widths and shapes can also be used for different line quality.
So here's my go at 'digital woodblock.' I had fun experimenting with the limitations of a three color run (on off white paper) rust, turquoise, and the black trap line. The turquoise over the rust gives the brown, simulating real, transparent printing ink.