The Painter has only a few tools, and these are very simple; they consist principally of the grinding stone, or _slab_ and _muller_, for grinding his colours; _earthen pots_ for holding the paints; _cans_ for oil and turps; a few tin pots, or open cans and kettles, for colour to be applied to outside places or walls where he has to work on ladders; a _palette knife_, for spreading the white lead on the stone, or removing the paint to the palette, for fine work, or to the paint pot; and _brushes_ of different sizes. [Illustration: Slab and Muller. Paint Pot. Palette Knife. Oil Can. Paint Pot. Paint Kettle.] The various colours, which are mostly made from earths and minerals, are purchased by the Painter in powder or small dry lumps, and have to be brought to a fine state, and made quite free from grit, before they can be used. The slab, or grindstone, is generally of marble or porphyry, and must have a perfectly smooth surface; and the muller is a large oval or egg-shaped pebble, with one end broken off, and the surface made as smooth as that of the slab. A small quantity of the colour which requires grinding is placed on the stone, and moistened with a little oil; and the muller is then worked over it, by a circular movement, until it is gradually driven to the edge of the stone. The colour is then removed by the spatula, or palette knife, and placed in the paint pot. [Illustration: Paint Brushes.] In this state, however, the colour is too thick to use, and of course requires to be thinned by adding the oil until it is sufficiently fluid. In painting woodwork, the first business is called “knotting,” that is, removing the turpentine from the knots, which would otherwise ooze and spoil the paint. They are first covered with fresh slaked lime, which dries up and burns out the turpentine; this is afterwards scraped off, and the knots painted with a mixture of red and white lead mixed with glue size, and afterwards with white lead and linseed oil. When dry, they must be rubbed smooth with a piece of pumice stone. The next operation is to put on the “priming,” which is the first coat of paint, composed of red and white lead and linseed oil. The nail-holes, and other imperfections, are then stopped up with putty (a mixture of linseed oil and whiting, made into a paste), applied with the _stopping knife_; and then the other coats of paint are laid on; three coats being generally considered sufficient; and the last being of the required colour. [Illustration: Stopping Knife.]