I have a Sewline. But I took a applique class with Ami Simms and she gave us an inexpensive Bic Pencil and it had the Sewline pencil lead in it, so save yourself the money of the pen and just stock up on lead for it. The pencil will say 0.9 mm on it and that is the same size as the lead from Sewline and Bohn, not sure about F&P. I really like them, haven't had trouble with markings not coming out.