I usually do at least some postwork, but I think this would be a fun challenge. The last time I entered a "no postwork" challenge, I learned how to displacement map my signature onto a rock, so it looked like it had been chiseled there. (Sort of - it was hard to get rid of all the texture stretching.)

OTOH, it seems like this could end up taking over the challenge. "Text without postwork" could be a render challenge all its own.