Question: Why Are They Called Non-Photo-Blue Pencils, And What Are They Used For?
In traditional animation, you often see the use of non-photo-blue pencils: pencils that draw with a light blue color much like a color pencil. Why do animators use them, and what does "non-photo-blue" mean?
Answer: Non-photo-blue pencils are used in traditional animation, where final inked drawings are still sometimes photocopied onto cels. These pencils are used to do sketches and final art refinements before the lines on each frame are retraced either with a dark pencil or with ink (most likely the pencil), often on top of the blue sketches, before running through the copier. Photocopiers often miss lighter colors, blending them in with the white background. While this may make some people curse, to animators it's a boon when the copier misses the light blue underneath the dark pencil and only copies the clean pencil lines to the animation cel. Hence the name non-photo-blue: because it's just the right shade for the photocopier to miss it.
