Andy Sperandeo wrote:

I've tried a few brands of artists' pencils in various gray and yellow shades, and they all worked. I wouldn't worry too much about a particular brand.

Not sure what you mean by "work," Andy, but my experience is like the others on the list who have found Prismacolor superior to other artist's pencils. At least one other brand, which I don't recall and may be repressing, did not work AT ALL for me. I seem to recall flinging it across the room . . . <g>