Painting Floor

Oil paint 

Oil paint  is a type of slow-drying paint that consists of particles of pigment suspended in a drying oil, commonly linseed oil. The viscosity of the paint may be modified by the addition of a solvent such as turpentine or white spirit, and varnish may be added to increase the glossiness of the dried oil paint film. 

Oil paints have been used in Europe since the 12th century for simple decoration, but were not widely adopted as an artistic medium until the early 15th century. Common modern applications of oil paint are in finishing and protection of wood in buildings and exposed metal structures such as ships and bridges. 

Its hard-wearing properties and luminous colors make it desirable for both interior and exterior use on wood and metal. Due to its slow-drying properties, it has recently been used in paint-on-glass animation. Thickness of coat has considerable bearing on time required for drying: thin coats of oil paint dry relatively quickly.

Oil painting  is the process of painting with pigments with a medium of drying oil as the binder. Commonly used drying oils include linseed oil, poppy seed oil, walnut oil, and safflower oil. 

The choice of oil imparts a range of properties to the oil paint, such as the amount of yellowing or drying time. Certain differences, depending on the oil, are also visible in the sheen of the paints. An artist might use several different oils in the same painting depending on specific pigments and effects desired. 

The paints themselves also develop a particular consistency depending on the medium. The oil may be boiled with a resin, such as pine resin or frankincense, to create a varnish prized for its body and gloss.

Although oil paint was first used for Buddhist paintings by painters in central and western Afghanistan sometime between the fifth and tenth centuries,it did not gain popularity until the 15th century. 

Its practice may have migrated westward during the Middle Ages. Oil paint eventually became the principal medium used for creating artworks as its advantages became widely known. The transition began with Early Netherlandish painting in Northern Europe, and by the height of the Renaissance oil painting techniques had almost completely replaced the use of tempera paints in the majority of Europe.

In recent years, water miscible oil paint has become available. Water-soluble paints are either engineered or an emulsifier has been added that allows them to be thinned with water rather than paint thinner, and allows, when sufficiently diluted, very fast drying times (1–3 days) when compared with traditional oils 

Traditional oil painting techniques often begin with the artist sketching the subject onto the canvas with charcoal or thinned paint. Oil paint is usually mixed with linseed oil, artist grade mineral spirits, or other solvents to make the paint thinner, faster or slower-drying. 

(Because these solvents thin the oil in the paint, they can also be used to clean paint brushes.) A basic rule of oil paint application is 'fat over lean', meaning that each additional layer of paint should contain more oil than the layer below to allow proper drying. 

If each additional layer contains less oil, the final painting will crack and peel. This rule does not ensure permanence; it is the quality and type of oil that leads to a strong and stable paint film.

There are many other media that can be used with the oil, including cold wax, resins, and varnishes. These additional media can aid the painter in adjusting the translucency of the paint, the sheen of the paint, the density or 'body' of the paint, and the ability of the paint to hold or conceal the brushstroke. These aspects of the paint are closely related to the expressive capacity of oil paint.

Traditionally, paint was transferred to the painting surface using paintbrushes, but there are other methods, including using palette knives and rags. Oil paint remains wet longer than many other types of artists' materials, enabling the artist to change the color, texture or form of the figure. At times, the painter might even remove an entire layer of paint and begin anew. 

This can be done with a rag and some turpentine for a time while the paint is wet, but after a while the hardened layer must be scraped. Oil paint dries by oxidation, not evaporation, and is usually dry to the touch within a span of two weeks (some colors dry within days). It is generally dry enough to be varnished in six months to a year.

Oil paint is made by mixing pigments of colors with an oil medium. Different colors are made, or purchased premixed, before painting begins, but further shades of color are usually obtained by mixing small quantities together as the painting process is underway. 

An artist's palette, traditionally a thin wood board held in the hand, is used for holding and mixing paints of different colors. Pigments may be any number of natural or synthetic substances with color, such as sulphides for yellow or cobalt salts for blue. 

Traditional pigments were based on minerals or plants, but many have proven unstable over long periods of time; the appearance of many old paintings today is very different from the original. Modern pigments often use synthetic chemicals. The pigment is mixed with oil, usually linseed, but other oils may be used. The various oils dry differently, which creates assorted effects.

Traditionally, artists mixed their own paints from raw pigments that they often ground themselves and medium. This made portability difficult and kept most painting activities confined to the studio.

 This changed in the 1800s, when tubes of oil paint became widely available following the American portrait painter John Goffe Rand's invention of the squeezable or collapsible metal tube in 1841 (the year of Claude Monet's birth). Artists could mix colors quickly and easily, which enabled, for the first time, relatively convenient plein air painting (a common approach in French Impressionism).

A brush is most commonly employed by the artist to apply the paint, often over a sketched outline of their subject (which could be in another medium). Brushes are made from a variety of fibers to create different effects.

 For example, brushes made with hog bristle might be used for bolder strokes and impasto textures. Fitch hair and mongoose hair brushes are fine and smooth, and thus answer well for portraits and detail work. 

Even more expensive are red sable brushes (weasel hair). The finest quality brushes are called "kolinsky sable"; these brush fibers are taken from the tail of the Siberian weasel. This hair keeps a superfine point, has smooth handling, and good memory (it returns to its original point when lifted off the canvas), known to artists as a brush's "snap".

Floppy fibers with no snap, such as squirrel hair, are generally not used by oil painters.In the past few decades, many synthetic brushes have been marketed. These are very durable and can be quite good, as well as cost efficient.

Brushes come in many sizes and are used for different purposes. The type of brush also makes a difference. For example, a "round" is a pointed brush used for detail work. "Flat" brushes are used to apply broad swaths of color. "Bright" is a flat brush with shorter brush hairs, used for "scrubbing in". "Filbert" is a flat brush with rounded corners. 

"Egbert" is a very long, and rare, filbert brush. The artist might also apply paint with a palette knife, which is a flat metal blade. A palette knife may also be used to remove paint from the canvas when necessary. A variety of unconventional tools, such as rags, sponges, and cotton swabs, may be used to apply or remove paint. Some artists even paint with their fingers.

Though the ancient Mediterranean civilizations of Greece, Rome, and Egypt used vegetable oils, there is little evidence to indicate their use as media in painting. Indeed, linseed oil was not used as a medium because of its tendency to dry very slowly, darken, and crack, unlike mastic and wax (the latter of which was used in encaustic painting).

Greek writers such as Aetius Amidenus recorded recipes involving the use of oils for drying, such as walnut, poppy, hempseed, pine nut, castor, and linseed. When thickened, the oils became resinous and could be used as varnish to seal and protect paintings from water. Additionally, when yellow pigment was added to oil, it could be spread over tin foil as a less expensive alternative to gold leaf.

Early Christian monks maintained these records and used the techniques in their own artworks. Theophilus Presbyter, a 12th-century German monk, recommended linseed oil but advocated against the use of olive oil due to its long drying time. Oil paint was mainly used as it is today in house decoration, as a tough waterproof cover for exposed woodwork, especially outdoors.

In the 13th century, oil was used to detail tempera paintings. In the 14th century, Cennino Cennini described a painting technique utilizing tempera painting covered by light layers of oil. The slow-drying properties of organic oils were commonly known to early painters. However, the difficulty in acquiring and working the materials meant that they were rarely used (and indeed the slow drying was seen as a disadvantage).

As public preference for naturalism increased, the quick-drying tempera paints became insufficient to achieve the very detailed and precise effects that oil could achieve. The Early Netherlandish painting of the 15th century saw the rise of the panel painting purely in oils, or oil painting, or works combining tempera and oil painting, and by the 16th century easel painting in pure oils had become the norm, using much the same techniques and materials found today. 

The claim by Vasari that Jan van Eyck "invented" oil painting, while it has cast a long shadow, is not correct, but van Eyck's use of oil paint achieved novel results in terms of precise detail and mixing colors wet-on-wet with a skill hardly equaled since. Van Eyck's mixture may have consisted of piled glass, calcined bones, and mineral pigments boiled in linseed oil until they reached a viscous state—or he may have simply used sun-thickened oils (slightly oxidized by Sun exposure). He left no written documentation.

The Flemish-trained or influenced Antonello da Messina, who Vasari wrongly credited with the introduction of oil paint to Italy, does seem to have improved the formula by adding litharge, or lead (II) oxide. The new mixture had a honey-like consistency and better drying properties (drying evenly without cracking).

This mixture was known as oglio cotto—"cooked oil." Leonardo da Vinci later improved these techniques by cooking the mixture at a very low temperature and adding 5 to 10% beeswax, which prevented darkening of the paint. Giorgione, Titian, and Tintoretto each may have altered this recipe for their own purposes.

The paint tube was invented in 1841 by portrait painter John Goffe Rand,superseding pig bladders and glass syringesas the primary tool of paint transport. Artists, or their assistants, previously ground each pigment by hand, carefully mixing the binding oil in the proper proportions. 

Paints could now be produced in bulk and sold in tin tubes with a cap. The cap could be screwed back on and the paints preserved for future use, providing flexibility and efficiency to painting outdoors. The manufactured paints had a balanced consistency that the artist could thin with oil, turpentine, or other mediums.

Paint in tubes also changed the way some artists approached painting. The artist Pierre-Auguste Renoir said, “Without tubes of paint, there would have been no impressionism.” For the impressionists, tubed paints offered an easily accessible variety of colors for their plein air palettes, motivating them to make spontaneous color choices. With greater quantities of preserved paint, they were able to apply paint more thickly.

Carrier:

Characteristics

Traditional oil paints require an oil that always hardens, forming a stable, impermeable film. Such oils are called causative, or drying, oils, and are characterised by high levels of polyunsaturated fatty acids. One common measure of the causative property of oils is iodine number, the number of grams of iodine one hundred grams of oil can absorb. 

Oils with an iodine number greater than 130 are considered drying, those with an iodine number of 115–130 are semi-drying, and those with an iodine number of less than 115 are non-drying. Linseed oil, the most prevalent vehicle for artists' oil paints, is a drying oil.

When exposed to air, oils do not undergo the same evaporation process that water does. Instead, they dry semisolid. The rate of this process can be very slow, depending on the oil.The advantage of the slow-drying quality of oil paint is that an artist can develop a painting gradually. Earlier media such as egg tempera dried quickly, which prevented the artist from making changes or corrections. 

With oil-based paints, revising was comparatively easy. The disadvantage is that a painting might take months or years to finish, which might disappoint an anxious patron. Oil paints blend well with each other, making subtle variations of color possible as well as creating many details of light and shadow. 

Oil paints can be diluted with turpentine or other thinning agents, which artists take advantage to paint in layers.There is also another kind of oil paint that is water-mixable, making the cleaning and using process easier and less toxic.

Sources

The earliest and still most commonly used vehicle is linseed oil, pressed from the seed of the flax plant. Modern processes use heat or steam to produce refined varieties of oil with fewer impurities, but many artists prefer cold-pressed oils.

Other vegetable oils such as hemp, poppy seed, walnut, sunflower, safflower, and soybean oils may be used as alternatives to linseed oil for a variety of reasons. For example, safflower and poppy oils are paler than linseed oil and allow for more vibrant whites straight from the tube.

Extraction methods and processing

Once the oil is extracted, additives are sometimes used to modify its chemical properties. In this way, the paint can be made to dry more quickly (if that is desired), or to have varying levels of gloss, like Liquin. 

Modern oils paints can, therefore, have complex chemical structures; for example, affecting resistance to UV. By hand, the process involves first mixing the paint pigment with the linseed oil to a crumbly mass on a glass or marble slab. 

Then, a small amount at a time is ground between the slab and a glass Muller (a round, flat-bottomed glass instrument with a hand grip). Pigment and oil are ground together 'with patience' until a smooth, ultra-fine paste is achieved. This paste is then placed into jars or metal paint tubes and labelled.