Thursday, 3 May 2018

THE PIGMENTS

THE PIGMENTS
An orangish red pigment. It's a mercury sulfide mineral (cinnabar) used from antiquity through to the present though only scarcely due to its toxicity. Made artificially from the 8th century (vermilion), it was the principle red in painting until the manufacture of its synthetic equivalent, cadmium red.
  •  History of use.
Used in China since Ancient times the pigment was known to the Greeks and Romans. According to Pliny the whole supply of vermilion came from Sisapo in Spain. The pigment was used up until the discovery of cadmium red, when its use dramatically reduced due to its known blackening upon reaction to hydrogen sulphides in the air.
  • Natural variety of pigment.
The mineral was crushed and purified by washing and heating.Two methods however emerged in its manufacture; that of the dry method, which was used by ancient alchemists and the wet method, which was developed in England, Germany and America.
  • Artificial variety of pigment.
Mercury is combined with molten sulfur,forming black amorphous HgS (a'-form), which is broken up and sublimated in earthenware pots, where its crystal structure reconfigures into red crystals (a-form).

The ground pigment:

TIME BROWSE LINE
Vermilion was discovered in the beginning of antiquity (Greece) or in 8th century and used until 19th century. 
                                                         PIGMENTS IN ACRYLICS
Acrylic is an appealing medium because of its versatility. When it is watered down, acrylic paint can become thin and watery like watercolours. Acrylic paint can also be applied thickly, mimicking the appearance of oil paints. Additionally, there are several different acrylic mediums, gels and pastes that artists can add to the paint to alter the texture, sheen, consistency, and various other characteristics of the acrylic paint.Acrylic paint consists of pigment suspended in a binder of acrylic polymer emulsion. Acrylics can be applied to the support in a number of different ways – via a paintbrush, palette knife, fingers, or just about anything. They can be used right from the jar or tube, although in most cases the paint is mixed on a palette first.
You can make acrylic paints by mixing pure powdered pigment with a binder and a solvent:
1.-Add water or a clear alcohol to a pile of pure ground pigment.
 2.- Mix with spatula.
3.- Once the pigments are completely dispersed, add the binder.
4.- Mix with spatula.
5.- The result is an acrylic paint that is similar to manufactured acrylic paint.
6.- Using a paintbrush, the acrylic paint is applied to a white canvas.