Derwent Inktense pencils are a product that is unique on the market. They are water-soluble, but with the vivid bright intensity of ink after water has been added. You cannot judge at all what the color will be once wet, by looking at the dry color, because the color shift between wet and dry is dramatic. Inktense pencils have been very popular, and Derwent also makes these in 'blocks' which look like the Prismacolor art styx. There are 71 colors available, and an Outliner (a water-soluble graphite pencil) comes with the sets, making 72 pencils. Inktense pencils can be a little crumbly when sharp and heavy pressure is applied.