Editing Oil painting (section)

==Process==
{{Unreferenced section|find=oil painting techniques|find2="oil painting tools"|date=July 2024}}
[[Image:Oil painting palette.jpg|thumb|A traditional wood [[Palette (painting)|palette]] used to hold and mix small amounts of paint while working|alt=A man's finger sticks through a hole in a large wooden palette. One of his hands is dipping a brush into the paint and the other holds numerous brushes in reserve.]]
Oil paint is made by mixing [[pigment]]s of colors with an oil medium. Since the 19th century the different main colors are purchased in [[paint tube]]s pre-prepared before painting begins, further shades of color are usually obtained by mixing small quantities 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. Pigments may be any number of natural or synthetic substances with color, such as [[sulfide]]s for yellow or cobalt salts for blue. Traditional pigments were based on minerals or plants, but many have proven unstable over long periods. 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.

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 bristles 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-hair brush|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 multiple 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 [[Fingerpaint|fingers]].

[[File: Tubes of paint, artist's paint PNG.png|thumb|left|Tubes of paint]]
Old masters usually applied paint in thin layers known as "glazes" that allow light to penetrate completely through the layer, a method also simply called "indirect painting". This technique is what gives oil paintings their luminous characteristics. This method was first perfected through an adaptation of the [[egg tempera]] painting technique (egg yolks used as a binder, mixed with pigment), and was applied by the [[Early Netherlandish painter]]s in Northern Europe with pigments usually ground in [[linseed oil]]. This approach has been called the "mixed technique" or "mixed method" in modern times. The first coat (the [[underpainting]]) is laid down, often painted with egg tempera or turpentine-thinned paint. This layer helps to "tone" the canvas and to cover the white of the gesso. Many artists use this layer to sketch out the composition. This first layer can be adjusted before proceeding further, an advantage over the "cartooning" method used in [[fresco]] technique. After this layer dries, the artist might then proceed by painting a "mosaic" of color swatches, working from darkest to lightest. The borders of the colors are blended when the "mosaic" is completed and then left to dry before applying details.

Artists in later periods, such as the [[Impressionism|Impressionist]] era (late 19th century), often expanded on this [[wet-on-wet]] method, blending the wet paint on the canvas without following the Renaissance-era approach of layering and glazing. This method is also called "[[alla prima]]". This method was created due to the advent of painting outdoors, instead of inside a studio, because while outside, an artist did not have the time to let each layer of paint dry before adding a new layer. Several contemporary artists use a combination of both techniques to add bold color (wet-on-wet) and obtain the depth of layers through glazing.

When the image is finished and has dried for up to a year, an artist often seals the work with a layer of varnish that is typically made from [[dammar gum]] crystals dissolved in turpentine. Such varnishes can be removed without disturbing the oil painting itself, to enable cleaning and [[Art Conservation and Restoration|conservation]]. Some contemporary artists decide not to varnish their work, preferring the surface unvarnished to avoid a glossy look.