where does graphite come from to make pencils
Graphite From the 16th century, all pencils were made with leads of English natural graphite, but modern pencil lead is most commonly a mix of powdered graphite and clay; it was invented by Nicolas-Jacques Conté in 1795.[39][40] It is chemically unrelated to the metal lead, whose ores had a similar appearance, hence the continuation of the name. Plumbago is another older term for natural graphite used for drawing, typically as a lump of the mineral without a wood casing. The term plumbago drawing is normally restricted to 17th and 18th century works, mostly portraits.
Base oil The least refined type which produced by Solvent Refining. It usually consists of conventional petroleum base oils.
Paint Pigments are granular solids incorporated in the paint to contribute color. Fillers are granular solids incorporate to impart toughness, texture, give the paint special properties,[13] or to reduce the cost of the paint. Alternatively, some paints contain dyes instead of or in combination with pigments.
En plein air Artists have long painted outdoors, but in the mid-19th century, working in natural light became particularly important to the Barbizon school, Hudson River School, and Impressionists.