Blackwork's great fun. It requires an amount of concentration (and co-ordination) but at the same time it's rather relaxing.
Here's the piece I did today. As you can see, the technique isn't necessarily always worked in black.
|Shading is achieves by using fewer strands or working less of the pattern|
I'd like to tackle this bird one day.
For information about this technique, see the Royal School of Needlework's website: http://www.royal-needlework.org.uk/content/36/.
This looks a fun blog: http://www.blackworkjourney.co.uk/
Also some good patterns are on this site: http://www.blackworkarchives.com/
... and The Blackwork Guild: http://www.theblackworkguild.com/