Copying pencil Copying pencil A copying pencil, also indelible pencil or chemical pencil, is pencil whose lead contains a dye. The lead is fabricated by adding a dry water-soluble permanent dye to powdered graphite—used in standard graphite pencils—before binding the mixture with clay. Copying pencils were introduced in the 1870s and were originally marketed for copying documents, especially for making permanent copies of a permanent original. This was achieved by creating a hand-written document using a copying pencil, laying a moist tissue paper over the document and pressing down with a mechanical press. The water-soluble dye in the writing would be transferred
Lead poisoning tens or hundreds of milligrams of lead. Eating chips of lead paint presents a particular hazard to children, generally producing more severe poisoning than occurs from dust. Because removing lead paint from dwellings, e.g. by sanding or torching creates lead-containing dust and fumes, it is generally safer to seal the lead paint under new paint (excepting moveable windows and doors, which create paint dust when operated). Alternatively, special precautions must be taken if the lead paint is to be removed. In oil painting it was once common for colours such as yellow or white to be made with lead carbonate.