I rarely use white paper in my own practice, so I usually stain the learners' paper before a class. Ink can be vibrant or subtle and forms a watery contrast to gritty charcoal, graphite and oil pastel. Emulsion (house) paint brushed on (and dried) is a wonderful textural surface to draw on - giving unpredictable marks. There's a lovely gouache paint and Indian ink technique that I use - a process that combines discipline and magical discovery.