I have the Bohin mechanical marking pencil - similar to the Sewline. My friend just bought the sewline brand over the weekend. Directions say erase or wash. Not sure if the lead sizes are interchangeable (prolly not). I love the Bohin that I have as well. Only have the white lead for it. For light fabrics I use a regular mechanical pencil with #2 lead. Have only had a problem with that washing out 1 time. If the leads aren't interchangeable I might have to switch over the the Sewline as they seem to have more colors available. Then again, might just have to check the office supply stores to see what sizes/colors of 'leads' they have and what the removal instructions are.