What is the difference between oil and acrylic painting?

Answer 1

the base of the paint

Answer 2

The basic difference is, of course, that they are made from different materials. But artistically, the differences are much greater than their mere physical capacities. Watercolour is the most delicate of the three. And, because the colours are water-soluble, they may not be painted over each other, as this results only in a blurring the image and producing a muddy colour. Water colour might be likened to sketching. There is a freshness and an immediacy to it, and you can not go back and re-do it. Oil is a traditional painting medium. The old masters worked in oil, and oil remains popular today. The oil paints can over overlayered -- this is a popular technique when painting sky, water, or shadows -- to paint an underlayer, which may be contrasting, or which may suggest details, and then paint over it with a different colour. This gives a very lively result. While the viewer can not see the undercolour, it does affect the texture and tone of the picture. This is especially true in portraiture, where the undercolours affect the appearance of skin tones. Where watercolour is muted, oils are quite lively, but nowhere near as alive as the acrylic paints. These have a glossy finish, and are most popular with modern style art. Portraiture is seldom done in acrylics, as the hard, shiny finish doesn't replicate the skin tones as well as oil paints do. Modern art, which so often relies on the hard edge for effect, is perfectly suited to acrylic paints. Underpainting has no effect in acrylics but the intensity of colour which can be achieved in acrylics is matched by no other paint. Hope this is helpful.

Answer 3

Oil paint needs a solvent such as turpentine, linseed oil or paint thinner to thin it. It takes a lot of time to dry. The positive points are that it leaves you a lot of time for perfect blending or changes and the colors are a bit richer. Acrylics can be thinned with water and brushes can be washed with water. The good point to acrylics is that you can get a painting done and dried fast.

Answer 4

Besides the difference in the basic ingredients,
>Oil cleans up with turpentine ( there are some new improved oils they claim are water clean-up, haven't tried them) and acrylics are water clean up.
>Oil have a much longer dry time--weeks. Acrylics are a plastic and harden up within minutes. Oils dry, acrylics harden.
>Oil can be reworked, or even scraped off a canvas. Acrylic has to be repainted.
>Oil and acrylic both have intense colors. Oil allows the time to blend colors on the palette and painting.
>Acrylics can dry on a brush in minutes and it's ruined. Oil doesn't harden like that.
>Acrylics can be painted on just about anything.
Both have their merits.
I mural paint in malls, sports arena etc and need to have a fast dry time with the paint as the businesses are often open and operating. I use flat latex wall paints.

Answer 5

Oil is oil base, acrylic is water base....
Oil is smelly, acrylic is not....
Oil dries so long, acrylic dries fast....
Oil messier, acrylic simpler....
Oil more expensive, acrylic more economic...
Oil is more alive when it's done, acrylic is more flat and cold....
.

Answer 6

Oil smells funny, and acrylic can be watered down.

Answer 7

Oil painting
Oil painting is done on surfaces with pigments that are ground and mixed into a medium of oil — especially in early modern Europe, linseed oil. Other oils occasionally used include poppyseed oil, walnut oil, and safflower oil. These oils give various properties to the oil paint, such as less yellowing or different drying times. Certain differences are also visible in the sheen of the paints depending on the oil. Painters often use different oils in the same painting depending on specific pigments and effects desired. The paints themselves also develop a particular feel depending on the mediums. A basic rule of oil paint application is 'fat over lean.' This means that each additional layer of paint should be a bit oilier than the layer below, to allow proper drying. Traditional oil painting techniques often begin with paint mixed with turpentine. As a painting gets additional layers, the paint must get oilier (leaner to fatter) or the final painting will crack and peel. There are many other painting mediums that can be used in oil painting, including cold wax, resins, and varnishes. These additional mediums 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 variable are closely related to the expressive capacity of oil paint. When looking at original oil paintings, the various traits of oil paint allow one to sense the choices the artist made as they applied the paint. For the viewer, the paint is still, but for the artist, the oil paint is a liquid or semi-liquid and must be moved 'onto' the painting surface. Traditionally, moving paint was accomplished with paint brushes, but there are other methods, including the palette knife, the rag, and even directly from the paint tube. Oil paint remains wet longer than many other types of artists' materials, so a reality in many painter's studios is the removal of oil paint from the painting. This can be done with a rag and some turpentine for a certain time while the paint is wet, but after a while, the hardened layer must be scraped. Many oil paintings reveal evidence of such scraping on close inspection, particularly when the surface itself is examined. Oil paint dries by oxidation, not evaporation, and is usually dry to the touch in a day to two weeks. It is generally dry enough to be varnished in six months to a year. Art conservators do not consider an oil painting completely dry until it is 60 to 80 years old.

Oil paint was probably developed for decorative or functional purposes in the High Middle Ages. Surfaces like shields — both those used in tournaments and those hung as decorations — were more durable when painted in oil-based media than when painted in the traditional tempera paints.

Many Renaissance sources credit northern European painters of the 15th century with the "invention" of painting with oil media on wood panel — Jan van Eyck is often mentioned as the "inventor". The popularity of oil grew in 16th century Venice, where a water-durable medium was essential. Oil painting was ideal for the northern European painters, because the preferred fresco painting media did not work as well in their cooler climate. The linseed oil itself comes from the flax seeds, and this flax was a common fiber crop. Recent advances in chemistry have produced modern water miscible oil paints that can be used with and cleaned up with water. Small alterations in the molecular structure of the oil creates this water miscible property.

A still-newer type of paint, heat-set oils, remain liquid until heated to 265–280 °F (130–138 °C) for about 15 minutes. Since the paint never dries otherwise, cleanup is not needed (except when one wants to use a different color and the same brush). Although not technically true oils (the medium is an unidentified "non-drying synthetic oily liquid, imbedded with a heat sensitive curing agent"), the paintings resemble oil paintings and are usually shown as oil paintings.

Process of oil painting
The process of oil painting varies from artist to artist, but often includes certain steps. First, the artist prepares the surface. Although surfaces like linoleum, wooden panel, pressed wood, and cardboard have been used, the most popular surface is canvas. While many famous paintings were painted on panel (for instance Da Vinci's Mona Lisa), panels are heavy, are vulnerable for cracking when the wood reacts to moisture and can generally only be fairly small. Stretched canvas has none of these problems.

Traditional artists' canvas is made from linen, but the less expensive cotton fabric has gained popularity. The artist first prepares a wooden frame called a “stretcher" or "strainer." The difference between the first and second is that stretchers are slightly adjustable, while strainers are rigid and lack adjustable corner notches. The canvas then pulled across the wooden frame and tacked or stapled tightly to the back edge. The next step is for the artist to apply a ground (or size) to isolate the canvas from the acidic qualities of the paint. Traditionally, the canvas was coated with a layer of rabbit skin glue and primed with subsequent layers of finely ground chalk (or marble dust) and rabbit skin glue. Later the process was changed to a sizing of rabbit skin glue with subsequent layers of white priming (gypsum, chalk, barium oxide, titianium(IV) dioxide mixed with linseed oil). Modern gessos are made of titianium dioxide with an acrylic binder and are not "real" gessos in the true sense of the word. The artist might apply several layers of gesso, sanding each smooth after it has dried. Sanding the primed surface is important to roughen the generally slick surface so the subsequent layers of oils will properly adhere. It is possible to tone the gesso to a particular color, but most store-bought gesso is white. The gesso layer will tend to draw the oil paint into the porous surface, depending on the thickness of the gesso layer. Excessive or uneven gesso layers are sometimes visible in the surface of finished paintings as a change in the layer that's not from the paint.

Next the artist might sketch an outline of their subject prior to applying pigment to the surface. “Pigment” may be any number of natural substances with color, such as sulfur for yellow or cobalt for blue. The pigment is mixed with oil, usually linseed oil but other oils may be used as well. The various oils dry differently creating assorted effects.

Traditionally, an artist mixed his or her own paints for each project. Handling and mixing the raw pigments and mediums was prohibitive to transportation. This changed in the late 1800’s, when oil paint in tubes became widely available. Artists could mix colors quickly and easily without having to grind their own pigments. Also, the portability of tube paints allowed for plein air, or outdoor painting (common to French Impressionism).

The artist most often uses a brush to apply the paint. Brushes are made from a variety of fibers to create different effects. For example, brushes made with hog’s bristle might be used for bolder strokes. Brushes made from miniver, which is squirrel fur, might be used for finer details. Sizes of brushes also create different effects. For example, a "round" is a pointed brush used for detail work. "Bright" brushes are used to apply broad swaths of color. 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. Some artists even paint with their fingers. [1]

Most artists paint in layers, a method first perfected in the Egg tempera painting technique, and adapted in Northern Europe for use with linseed oil paints. The first coat or "underpainting" is laid down first, painted normally with turpentine thinned paint. This layer helps to "tone" the canvas, and cover the white of the gesso. Many artists use this layer to sketch out the composition. This layer can be adjusted before moving forward, which is an advantage over the 'cartooning' method used in Fresco technique. After this layer dries, one way the artist might then proceed is by painting a "mosaic" of color swatches, working from darkest to lightest. The borders of the colors are blended together when the "mosaic" is completed. This layer is then left to dry before applying details. After it is dry, the artist will apply "glazes" to the painting, using a process of "Fat over Lean" which means more oil/paint ratio than the previous layer. A classical work might take weeks or even months to layer the paint. Artists in later periods such as the impressionist era often blended the wet paint on the canvas without following the Renaissance layering and glazing method. This method is called "Alla Prima." When the image is finished and dried for up to a year, an artist would often seal the work with a layer of varnish typically made from damar gum crystals dissolved in turpentine. Contemporary artists increasingly resist the varnishing of their work, preferring that the surfaces remain varnish-free indefinitely.

and

Acrylic paint
Acrylic paint is fast-drying paint containing pigment suspended in an acrylic polymer emulsion. Acrylic paints can be diluted with water, but become water-resistant when dry. Depending on how much the paint is diluted (with water) or modified with acrylic gels, mediums, or pastes, the finished acrylic painting can resemble a watercolor or an oil painting or have its own unique characteristics not attainable by oil or watercolor.

Acrylics were first available commercially in the 1950s. The first commercially available artist acrylic paints were mineral spirit based paints from a company called Bocour Artist Colors. The waterbased acrylic paints came later and were coined the term "latex" housepaints, although there is not any actual latex from a rubber tree in an acrylic dispersion. Interior "latex" housepaints tend to be a combination of binder (sometimes acrylic, vinyl, pva and others), filler, pigment and water. Exterior "latex" housepaints may also be a "co-polymer" blend, but the very best exterior waterbased paints are 100% acrylic based. Soon after the waterbased acrylic binders were introduced as housepaints, artists (the first artists were Mexican muralists) and companies alike began to explore the potential of the new binders.

Acrylic Artist Paints are their own unique media. They can be thinned with water and made into washes to be used similar to how watercolor paints are used, but the washes are not water sensitive and color lifting techniques are not as easy to do with acrylics as they are with true gum-arabic based watercolor paints.

The main difference of acrylics and oil paints is the inherent drying time. Oils allow for more time to blend colors and apply even glazes over underpaintings, etc. This slow drying aspect of oil can be seen as an advantage for certain techniques, but in other regards it impedes the artist trying to work quickly. The fast evaporation of water from the acrylic paint film can be slowed with the use of retarders. Retarders are generally glycol or glycerine based additives. In the case of acrylic paints, the addition of a retarder slows the evaporation rate of the water, and allows for more water to be added and the paint workable, until the retarder has left the film and the paint layer is dry.

Oil Paints have several disadvantages to acrylics, however. First, they tend to require the addition of a toxic solvent, such as mineral spirits or turpentine to thin the paints and clean up tools, though relatively recently water soluble oil paints have been developed for artist use. Secondly, oil paint films become increasing yellow and brittle, and will lose their flexibility in a few decades. Thirdly, the rules of "fat over lean" must be employed to ensure the paint films are durable.

Oil paint is able to absorb more pigment than acrylic because linseed oil has a smaller molecule than acrylic. Oil has a different Refractive Index than Acrylic dispersions. This changes how light interatcts with the paint films.

Acrylic paints can be made to be either a high gloss, matte or anywhere in between. As with oils, pigment amounts and particle size can alter the paint sheen. Likewise matting agents can be added to dull the finish. Topcoats or vanishes may also be applied to alter sheen.

Acrylic Paint is generally non removable when it is dry. Water or mild solvents do not resolublize it, although isopropyl alcohol can lift some fresh paint films off. Tolunene and Acetone can remove paint films, but they do not lift paint stains very well and are not selective, meaning using a solvent to remove paint will result in removing all of the paint layers, gesso, etc.

Using house-hold latex based paint as a primer for acrylic causes cracking after only a few years, especially if the painting is rolled for storage. Only use a proper, artist grade acrylic gesso to prime your canvas for use with acrylic. Acrylic will not form a stable paint film if it has been thinned with too much water (more than 50% is too much). However, the viscosity of acrylic can successfully be reduced by using suitable extenders that maintain the integrity the paint film (e.g. Golden Acrylic Glazing Medium, Liquitex Gloss Medium and Varnish).

Painters before the 20th Century have mixed their own paints to increase the longevity of the artwork and achieve desired pigment load, viscosity, and control exactly what fillers, if any, are used. While suitable mediums and raw pigments are available for producing your own acrylic paint, due to their fast drying time, hand mixing may not be as practical for the acrylic painter as it may be for an oil painter.

Acrylic painters modify the appearance, hardness, flexibility, texture, and other characteristics of the paint surface using acrylic mediums. Watercolor and oil painters also use various mediums, but the range of acrylic mediums is much greater. Acrylics have the ability to bond to many different surfaces, and mediums can be used to adjust their binding characteristics. Acrylic paint can change the sheen from gloss to matte, or can add iridescence or texture to the surface. They can also be used to build thick layers of paint: gel and molding paste mediums are sometimes used to create paintings with relief features that are literally sculptural.

Acrylic paints are the most commonly used in grattage (q.v.).

Acrylic paintings should ideally be recognized as being different from oil paintings. Acrylic paintings are a distinct art medium with its own advantages as well as limitations, rather than as a stand-in for other mediums. There are techniques which are available only to acrylic painters, as well as restrictions unique to acrylic painting. Therefore, judging an acrylic painting as though it were an oil painting (or a watercolor) is not always appropriate. Due to acrylic's more flexible nature and far more consistent drying time between colours, the painter does not have to follow the "fat over lean" rule of oil painting, where more medium must be applied to each layer to avoid cracking. While canvas needs to be properly primed and gessoed before painting with oil, acrylic can be safely applied to raw canvas. The fast drying time forces the acrylic painter to work at a much faster pace than an oil painter, or abandon blending all together. While acrylic retarders can slow drying time to several hours, it still doesn't come close to the 3 days or more of open time found in oil paint, and the addition of too much acrylic retarder can prevent the paint from ever drying properly.

Although the permanency of acrylics is sometimes debated by conservators, they appear more stable than oil paints. Whereas oil paints normally turn yellow as they age/dry(oxidize), acrylic paints, at least in the 50 years since invention, do not yellow, crack, or change.

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