Chinagraph pencils are a permanent marking pencil. They have the unique ability
to mark surfaces that resist other pens and pencils, such as metal, glass,
plastic, film, leather and stone. They even work on some wet surfaces.
is considered permanent (and waterproof) but can be removed with spirit
Staedtler have now changed the name of Chinagraph to Lumocolor Permanent Glasochrom. Available below in singles and boxes.