One of the few places selling frisket paper, sometimes
used by coloured pencil artists to remove unwanted colour. Also the place to go for battery operated erasers.
Good for other stuff too. www.millers-art.co.uk
1Buy 1 Pencils
Cheapest place I have found (up to now) for buying single
Karisma and Prismacolor pencils and sets www.1buy1pencils.co.uk