Yes, here they are. Mikey's infamous value spheres. They are everywhere, and they pop up randomly. It is the most direct way to test the working properties of a medium or surface.
Occasionally, I will do one just to tighten my chops, to stimulate my brain, or perhaps just to pass the time. Constructing a circle from scratch - by hand, with no drafting tools - is a good way to fire up my synapses and get the juices flowing.
This is a joy, nothing but pure form and light.
In these examples I am trying out the various colors of Derwent Drawing pencils on various papers:
The two colors yield very different surface qualities, yet they are the same brand, the same line, on the same piece of acid-free card stock.
The one on the left is Derwent Drawing #6300 Venetian Red. The one on the right is Derwent Drawing #66 Chocolate.
The Venetian Red has a grainier surface quality and the darks are punchier. The Chocolate has a finer surface quality with more subtlety in the lights, and the darks took much longer to build up. Quite the opposite of what I was expecting.
Here is the Venetian Red on parchment colored acid-free card stock. Ooooh, parchment: