I have tried to use many diffrent types of taylors chalk in the past to trace my patterns onto fabric.  I have found one that is just great to use. A must have in my sewing room.  It is a chalk machanical pencil.  It comes with an array of diffrent colors of chalk.  Im sure you can find it at any sewing store in with the other taylors chalk .  I use mine when I am tracing patterns, marking patterns, and making appliques.  It works great without worring about ruining your fabric.  Usually by the time my project is sewn the marks from the chalk are gone.  I use mine all the time.