User:Tokenzero/List of colorants used in painting

This is a list of colorants (both pigments and dyes) used in painting.

No colorant gives an exact, specific hue; even pure mineral pigments give a range of hues depending, e.g., on the size of crystals.

Beside hue, several other properties are important in painting:
 * Opacity or transparency – opaque colorants are ‘stronger’, but also easier to mix into smooth transitions and to use in structural techniques such as impasto. However, transparency is important for glaze when working in layers. Inorganic pigments are usually more opaque. Opacity may depend on the medium (as in oil color vs watercolor), additives, and the manufacturing process.
 * Bleeding – the undesirable effect of pigments from lower layers migrating to the surface. Typical to certain cheaper synthetic organic pigments, due to the small size of pigment particles.
 * Durability – most of all lightfastness, that is, the resistance from fading due to light exposure. Additionally, some substances or mixes are prone to other reactions that may change the color.
 * Toxicity – many historical pigments are withdrawn from use (excepting restoration) due to toxicity, especially from heavy metals. Others may be carcinogenic or teratogenic (harmful to pregnancy). Very few colorants are edible and care should always be taken to avoid inhaling dry pigments and excessive skin contact.
 * The effect on the speed of oil drying (or more properly, curing). Siccative pigments (mostly natural mineral pigments, containing lead, cobalt, or mangan) fasten the drying process. This is also relevant in egg tempera, where the drying is particularly slow.
 * Heat stability is relevant in ceramic painting.