[william]

Sorry if this sounds very noobish. I often see drawings done with a blue pencil. Is there a specific reason people do this?
thanks!!

[Jimmyjimjim]

The blue pencils you're talking about are called "Non-Photo-Blue" pencils. In the old days (before computers) people used them for layout purposes because they don't reproduce under a photostat or photocopier.

Nowadays, people usually use them to rough out a drawing(A scanner will see them just fine). They are a color that doesn't stand out and enables you to see the rough sketch under a drawing without detracting from it.

If anyone else has anything to add...

[egerie]

Jimmyjimjim pretty much covered it all. Those pencils are also refered to as "col-erase" as many use the sanford's col-erase indigo blue to sketch and rough out poses/frames.
It's a lot easyer to get rid of the blue pencil line when you scan a drawing. For example, some animation softwares like Retas can isolate your clean line (standard graphite pencil line) from your "blues". blah blah blah </shutsup>
Cheers!