Black and white illustrations I usually do with a pen, sometimes with a brush, using black ink, and I have 
recently enjoyed drawing with marvellous Japanese pens with metal tips of subtly differentiated thicknesses. 
I used to paint colour illustrations with tempera, until water-colour inks appeared on the market. 
Generally speaking, the free market has meant that I am wallowing in material delights, 
such as water-colour pencils, wonderful papers from all over the world, 
various pastels, paints and brushes. 
It takes considerable persuasion or force to drag me out of the ‘artists’ materials’ shop.