Pigment - SpeedyLook encyclopedia

History

The dyes known and were used since highest Antiquité. Sumériens, Greek, Roman, Egyptian, Mayas, etc used them abundantly, in particular like cosmetic products .

However, these dyes, in spite of their very great effectiveness, are not used any more because they highly contained metal salts toxic like arsenates, carbonate of Cuivre or Vert-de-gris , Céruse without forgetting the Antimoine, the mercury, the Plomb, etc

Botany

Organic substance producing the color constitutive of the elements of the plant:

sheets: Chlorophyl, Anthocyanes (or lipochromes)… red, blue or purple E 163;
trunk:
roots: Carotene,

The principal natural pigments (Dye S) extracted the plants include/understand:

the Indigo drawn from the Indigotier,
the Pale blue drawn from the pastel;
the saffron drawn from the Crocus sativus . Far in front of the Caviar and the Truffle S, it is the food product expensive in the world since it is usually negotiated around 2000 euros kg… One needs 160000 flowers to make one kilo of saffron.
alizarin and purpurin, reds drawn from the garance, small shrub of the Mediterranean Scrubland. This bright red coloured until in 1915 the pants of the Poilu S;
of the Terpene S like the Lycopene (red of radish and tomato) and the Carotene (orange of carrots);
the Charcoal, coal of homonymous wood.

Medicine

the most known pigment is the Mélanine, substance produced by the Mélanocytes.

Two types of mélanine are known:

the mélanine- bases or Eumélanine (it is a polymer) (brown-black),
the Phéomélanine of color yellow-red (it is a monomer). Present in the eyes and the Superficial body growth S skins, nails and hair, it gives the beauty spots, the Bronzage but the Dégénérescence of these cells gives the Mélanome frightening cancerous tumor in the form of the MMC. Whereas bronzing has as a role (in addition to providing Vitamine D) to protect the clear skins from UVA/UVB of the Sun.

The congenital absence of mélanine produces the Albinisme.

The eye, him is protected by contracting the iris, classically: until the size of a Pinhead. The excess of UV, as well as the traumatisms, involves the cataract.

in the eyes, the pigments, mélanines and Lipofuscine (green eyes) colors the iris in green, gray, black, hazel nut…

Whereas pigments in very small quantity give the blue eyes. This iris can sometimes be red in the complete absence of pigment (e.g. in the event of albinism).

In the vessels of the mammals: the hemoglobin blood equivalent of chlorophyl gives a red Glowing.

Mineralogy

We find all the pallet there:

- Ocher S,

- Ground S: of His and Ombrie, natural or burned. Very much used in painting (blood and different) but also on the Mediterranean Circumference to color the frontages of the houses in red, yellow, etc

Zoology

The natural dyes include/understand:

it Crimson drawn from a shell: the murex which colors since millenia the dress of the senators or cardinals with Rome,

it Carmine drawn from the cochineal,

Chemistry

Since the 19th century, the natural dyes, were generally replaced by synthetic compounds, azo drawn from the Aniline.

Food

If the Rouge of beet Exxx is quite inoffensive, other pigments dyes were it hardly, like:

it Yellow-of-butter Exxx which was used to color the margarines,

- the amaranth Exxx, red dye,…

They were precisely condemned by the Académie of Medicine as carcinogenic although they were largely used in the previous centuries.

does there exist about It still of others?

See: food Dye

Painting

Nowadays, the majority of the pigments are of industrial origin. Only some pigments are extracted starting from minerals, like ochers. The worldwide production of certain pigments as the Blanc of titanium rises to several hundred tons per annum.

In painting, qualities necessary for the pigments are:

stability with the light. Certain pigments are faded when they are exposed to the light, they are thus to avoid in painting.
the stablility mixes some with other pigments. To obtain varied colors, it is necessary to mix different pigments. It is important that those do not react between-them. For example, the cadmium pigments should not be mixed with pigments containing of lead.
Example:

of oil (Oil-base paint)
of water (Gouache)
of egg (Moderated)
etc

For blue:

blue of Prussian blue cobalt
blue overseas
blue of phthalocyanine
(plant), is not used any more
lapis lazuli (mineral), is not used any more, it is replaced by blue overseas.

for the Black plants:

Black of vine
Black of campêche
Lampblack and/or Black of soot and/or Lampblack
other vegetable blacks.

for the Black minerals:

Black of vase;
Black of Black Mars or iron ;
Black of manganese;
Black of Prussia;
the Ground of Cassel;
the Bitumen of Judaea;
the Kohl (but much more used in Cosmetic;
other mineral blacks.

for the reds (and pinks)

vegetable: garance, alizarin, Carmine, Crimson Kermes and S… others Red plants.

Without forgetting the Orchil, or French crimson, drawn from a lichen, Roccella tinctoria , (semi-alga, semi-mushroom) of the family of the Roccellaceae .

N.B. : the pink is generally obtained by deterioration of the red.

for the reds (and pinks) mineral: Vermilion and Cinnabar; Minium; Cadmium Red; red Grounds: Red of Pouzzoles, Red Van Dyck, different etc Red minerals.

the yellow, luminous color, very much used, in painting, is there the intermediary between gold and orange.

of the mineral yellows: Chromium Yellow; Yellow auréolin or Yellow Auréoline, of Hansa. The Orpiment (or Yellow royal, Yellow of Persia and Yellow arsenic of Persia, arsenic Yellow, Gold of insane the…). Yellow of Yellow cobalt, zinc or Yellow gold button, Yellow barium Yellow or of overseas, baryta Yellow, strontia Yellow, Yellow of turbith, Yellow of mummy, others yellow minerals.
of the vegetable yellows: Yellow saffron and Curcuma, Yellow Indian, Yellow Gum gutte or of Kampuchea, Quercitrin and Quercitron, others yellow plants;
of the yellows of synthesis: Azo.

for the orange or orange used in Painting, one encounters a great difficulty: “to classify, the Gamme of the colors (or Nuancier) this intermediate color enters the red and the yellow” Van Dyck.

cadmium oranges (cadmium sulfo-séléniures); the orange one of Mars or ground of Mars (oxide-of-iron), minium, true mine of reds oranges, the orange red one of Turkey-red cotton; the red of carthame (almost orange), the cobalt arsenate goes from the red to the toxic yellow, but hyper-, it was replaced by the orange cobalt yellow (another cobalt salt), orange the traditional Persan ones (of various compositions).
only one orange plant: the Yellow Gum gutte or of Kampuchea. It also, can be, yellow or orange according to its composition.

Cosmetic

See too

Internal bond

External bonds

the Web site of the French painter Guillaume Baube, www.lebaube.fr
bases in painting chapter 2
pigments, colors (Dotapea.com section)
illumination
video Document: " Pigments and old Dye S - spectroscopic Studies " (duration: 17 minutes)

Simple: Pigment

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