I was feeling a bit uninspired in the studio the other day, and started using my finger to apply thick white paint to some of the 4"x4" pieces that had been in limbo. Then I scribbled with graphite into the wet paint. Futzed around with a few more things, then gave it up as an uninspired studio day and went back to the "office" (my laptop). Came in this morning and LOOK! The white paint CRACKLED! I scanned these at high resolution so you can see the crackle.
The paint is Blick's Studio Acrylics, titanium white.
Graphite is Lyra, 9B; I use both water soluble and non-water soluble.
4"x4"x400 Project is described here.
To join in and post your own 4"x4" pieces, or just for inspiration, see the Flickr Group.