Liquid
Material that is liquid, traditionally is used by the Artist; water, turpentine, oil or acrylic.
Rock
Formed from earth
• primary: a hard material such as stone, lava, etc..
• secondary : stones; the sediment such as marble, limestone, sand or clay.
Organic
Matter such as wood, or leaf-shaped life (cell of veins and blockage)
• Fibrous
• [...]