Sharpie pens are made by Sanford, marks most anything, water
resistant, quick drying, come in various fine points, etc. Non toxic,
conforms to ASTM D-4236, made in the US. I buy them by the dozen in a
box at stationary/office supply stores. Whilst I have the box last
bought in front of me, there is no address for the company, but
perhaps they have a web site? Item number 30001 black for the fine
point. Hope this helps.