|I was getting frustrated with pencils and (even worse) pens for tracing patterns onto tracing paper, and markers of course bleed through. So the other day I tried out a china marker -- the kind you use to label china, glass, and other hard materials. I was slightly nervous about trying this, since the name in French is "mine grasse" -- greasy lead -- so I tried it first on a scrap piece of tracing paper (the kind that comes in a roll, from the art store). Not only was it not greasy, it didn't smear even when I tested it by rubbing one piece of marked tracing paper with another piece. It's also very smooth to write with, and -- not that you would need this with paper! -- waterproof. And it doesn't seem to bleed through at all to the other side of the tracing paper (I haven't tried it on super lightweight tracing paper yet, but you probably wouldn't be using that for tracing patterns anyway).
The picture above shows one of the brands available -- there are others. I didn't see the colored china markers (shown in the photo), just black, but you might be able to find colored ones in a large stationery store, discount store, or hardware store -- maybe even an art supply store. (A variety of colors would be even more useful, wouldn't it! I'm also going to try the colored ones for artwork if I ever track them down.)
P.S. They have a kind of paper wrapping next to the tip of the lead, and when they get stubby you "sharpen" them by pulling the string back a bit and peeling away some the paper.