Writing or drawing instrument consisting of a slender rod of graphite or similar substance encased in a cylinder of wood (or less usually metal or plastic). Although the material is graphite (a form of carbon), the term ‘lead’ pencil came into use because it superseded the lead point (see metalpoint). The first known reference to a wooden pencil dates from the 1560s, but instruments of predetermined hardness or softness were not produced until 1790, when Nicolas-Jacques Conté undertook to solve the problem of making pencils when France was cut off from the English supply of graphite (the mines in Borrowdale, Cumbria, which had opened in 1664, being the main source). He found that the graphite could be eked out with clay and fired in a kiln, and that more clay meant a harder pencil. Conté obtained a patent for his process in 1795. It was only then that the pencil became the universal drawing instrument that it is today. Ingres, who often used pencil with great delicacy in his portrait drawings, was one of the first to show its potential. Although the Oxford English Dictionary records the usage of the phrase ‘a pencil of black lead’ as early as 1612, until the end of the 18th century (or even later) the word ‘pencil’ more commonly meant a brush (particularly a small brush). ‘Pencilling’ could mean ‘colouring’ or ‘brushwork’ as well as ‘drawing’.