The ArtGraf Monochromatic set of pigment blocks comes with opaque white, graphite grey and carbon black.
As you can get but the colour selection, this set is for tonal studies, monochromatic work.
This is a quick sketch I painted using the three colours.
The graphite block but unfortunately it doesn't dissolve easily with a wet brush. You can wet it but all you'll get is a light value grey wash. To dissolve the graphite more easily, apply the graphite on the paper first before dissolving it. If your paper has lots of texture, it make take longer to dissolve the graphite completely to get rid of the solid graphite.
This could be one way to create textures. But some watercolour paper texture can have noticeable pattern so that obviously is going to look distracting.
The graphite is going to have the typical graphite sheen when viewed under certain angles.
If you want graphite that you can dissolve and apply thickly, consider the ArtGraf watersoluble graphite in tin. Add a bit of water and you can get it darker and more black faster than Carbon Black.
The Carbon Black block is much easier to dissolve with a wet brush. You can load a brush with lots of pigment in one stroke. All three colours are very transparent so they are great for painting over pen and ink.
When dry, the graphite and Carbon Black will both lighten. So it takes some time to get used to how much they will lighten.
These are also quite permanent when dry. You can use an eraser or kneaded eraser to pick up some pigment, but I would consider them permanent when dry.
The white block also dissolves easily and is surprisingly very opaque. That's great for covering over the greys or black to create highlights.
You can also use the white block to draw and create some textures. But the more you draw on the edge, the more blunt it's going to get.
Overall, the quality is good. This is a good set for quick tonal studies or monochromatic paintings. The set is expensive, relatively speaking, but the blocks are big and should last for a long time.
You can find the ArtGraf monochromatic set below: