I found some new pencils with different blacknesses so I experimented with tone swatches. I’m aiming to have at least three tones plus white. Four tones seem possible but it’s tricky to keep a clean separation in tone because each pencil can look like a darker shade if you press hard enough. It will need control to apply the swatches. I’ll keep the swatches by me so I know when the tone is right for each tone level. I need a reference card.