Painting is the practice of applying paint, pigment, color or other medium to a solid surface (support base). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and airbrushes, can be used.
John Opie, when asked with what he mixed his colors. See Samuel Smiles, Self Help, Chapter V. In Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 576-77.