Originally Posted by
117becca
i use frixion pens for all that i can. I have used the white ceramic pencils pretty successfully for marking dark fabrics.
The ceramic pencils are the best for marking accurately. I have a BOHN (France) pencil. It works like an eversharp and you can buy different colored leads for it. I just made a pile of Boston Blocks and used it on black with white lead. I needed the line to be exactly in the right spot, or the blocks might turn out wonky.
The leads are very expensive, but once you have paid for it, you will have enough for life and more. You could share leads with friends, also.
I just don't think a soap sliver would be consistently sharp enough.