Product FAQs
- What is lightfastness?
- What's the difference between the graphite degrees?
- How are degrees made and controlled?
- Are Derwent pencils non-toxic?
- My pastel pencil won’t sharpen, it keeps breaking.
- Is the Inktense range permanent?
A measure of how quickly something will change when exposed to UV light (sunlight). Light can cause colour to whiten, darken, fade or completely disappear. Lightfastness refers to the chemical stability of a pigment under long exposure to light. Our colours are rated on a scale of 1 to 8, the higher the number the better lightfast rating it has, so a colour with a rating of 8 will react more slowly when exposed to light.
B stands for BLACK and H stands for HARD. 9B is very soft & black and 9H is very hard & pale in shade. HB is half way between the two. F degree was made (stands for FINE) for doing shorthand in the days before computers!
By varying the proportions of clay and graphite. More graphite means a softer, blacker degree. More clay means a harder degree. HB has 50:50 clay and graphite.
Yes, all of our pencils are non-toxic.
Pastels are more delicate than normal pencils so they need to be handled with care during sharpening. Also the materials used to make pastel pencils are more abrasive than the materials in other pencils so the blades in sharpeners and craft knives will blunt more quickly. We recommend using a craft knife or special pastel sharpener and replacing them regularly to keep the blades sharp.
Yes, the Inktense pencils and blocks, once the pigment is dissolved fully in water, become permanent when dry. You can then work on top of this layer. The colour is vibrant and like an ink.