Marking Pencils

Way back when the old BB was up and running, someone suggested using a Prismacolor pencil for marking quilts. I bought one but have no idea where I got it - I do believe it was from someplace recommended by the poster. I really like this pencil - the lead doesn't break easily, it makes good marks, it stays on, but it comes off easily with just a little rubbing. I think Prismacolor pencils are more of an artists pencil - I've found large sets of many colors and also large sets of white at Hobby Lobby and Michaels and also through Google. But I'd love to know where I can just by a couple of them, not in packaged sets. Does anyone remember this or know who might carry them?? Thanks.......NancyH