I agree that redwork and bluework are just color choices, but blackwork is a bit different.
Whitework is basically white thread on white fabric.
Thank you. Looking at the blackwork article it looks very similar to cross stitch.
Yes, they did say worked on evenweave fabric. Chicken scratch comes to mind.
Thanks for the links. The older designs I have in blackwork really look like the traditional style. But, I think some are labeled blackwork for desings merely done in black thread.