{"id":1209785,"date":"2017-06-06T15:09:57","date_gmt":"2017-06-06T14:09:57","guid":{"rendered":"https:\/\/www.jacksonsart.com\/blog\/?p=1209785"},"modified":"2026-03-31T15:30:54","modified_gmt":"2026-03-31T14:30:54","slug":"oil-paint-guide","status":"publish","type":"post","link":"https:\/\/www.jacksonsart.com\/blog\/2017\/06\/06\/oil-paint-guide\/","title":{"rendered":"Oil Painting Guide: Paints and Mediums"},"content":{"rendered":"

This Oil Paint Guide aims to give a broad overview of some useful and interesting information about working in this medium. Oil paint<\/a> is a special medium that gives beautiful results. By understanding the structure, best practices, how to modify colours with oil mediums, and the available options, you can make the most of the time-honoured medium of oil painting. If you have any further questions please ask them by submitting a comment, underneath the post.<\/p>\n

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Contents:<\/h2>\n

What Makes Oil Paint So Special?<\/a><\/strong><\/p>\n

How is Oil Paint Made?<\/a><\/strong><\/p>\n

Drying Oils<\/a><\/strong><\/p>\n

How Oil Paints Dry and the Fat Over Lean Rule<\/a><\/strong><\/p>\n

What is the Difference Between Traditional Oils, Water-mixable Oils, Alkyd Oils and Oil Sticks?<\/a><\/strong><\/p>\n

Which Brand?<\/a><\/strong><\/p>\n

Same Colour Name, Different Colour<\/a><\/strong><\/p>\n

What Mediums Do I Need?<\/a><\/strong><\/p>\n

Varnish<\/a><\/strong><\/p>\n

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What Makes Oil Paint So Special?<\/h2>\n

Lustrous and versatile, oil paint has appealed to artists since the middle ages. Painters from Jan Van Eyck to Gerhard Richter have been drawn to its rich sheen and vibrant colour.\u00a0Many oil paint recipes used by the world\u2019s finest paintmakers have hardly changed for hundreds of years. There\u2019s no need – colour simply cannot appear any richer or more beautiful.<\/p>\n

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Paint impasto or paint in thin transparent layers!<\/figcaption><\/figure>\n<\/div>\n

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How is Oil Paint Made?<\/h2>\n

Oil paint has been around for thousands of years. The oldest evidence of oil paint dates back to 650 AD, in the Bamiyan Valley Caves of Afghanistan where the paint was used to paint Buddhist murals. The oil paint was likely made from natural resins, gums, and animal proteins.<\/p>\n

Since the 1400s, artists have favoured linseed oil as the most popular drying oil because it allows easy application of paint in layers with varying consistency. Its versatility also makes blending and glazing effortless. Like all drying oils, linseed oil reacts with oxygen, causing it to harden. This encases the pigment, helping to maintain colour vibrancy for hundreds of years.<\/p>\n

Although some naturally sourced pigments, like ochres and iron oxides, have been used to make paint since prehistoric times and continue to be used today, modern oil paint manufacturing relies heavily on synthetically developed pigments. For example, Vermilion is created by mixing mercury and sulfur, heating the mixture, allowing it to re-condense, and then removing and grinding the mercury. Prussian Blue is also commonly used. Ensuring the stability of pigments is crucial. They must be lightfast to prevent fading, resistant to damage from solvents like turpentine, have the correct pH balance with the drying oil to avoid acidity that could bleach the colour, and not react chemically with other pigments used in oil paint production.<\/p>\n

Pigment Characteristics<\/h2>\n

Each pigment has its own set of characteristics including particle size, transparency, and absorbency. These characteristics determine what ratio of oil to pigment is used in the paint, and the extent to which colours are ground\/milled during manufacturing. Oil paint manufacturers can take several years to test and refine the process of achieving the purest and most stable colours from their ingredients.<\/p>\n

Dispersing the Pigment Evenly Into the Oil<\/h2>\n

Most oil paint manufacturers use a machine called an ‘Automatic Muller’. It consists of two metal discs that rotate in opposite directions, evenly dispersing pigment into a drying oil. Artists who make their own paint at home typically use a non-automatic glass slab and muller, mixing the pigment and oil in a continuous circular motion.<\/p>\n

Several samples are made, each with slightly different proportions of drying oil to pigment. These samples are then tested to find the best recipe. A small quantity is spread across a piece of card with a palette knife. Another small quantity is mixed with a little white so that the paintmakers can compare the body colour of the paint as well as its tint. Once the best recipe is identified, mass production commences.<\/p>\n

Mass Production of Oil Paint<\/h2>\n

The quantities of linseed oil and pigment are multiplied by the same amount to ensure that the proportions of each are right for achieving the best colour. These are then put into the mixer; a big metal drum with an automated mixing device. The purest colours are made with a single pigment, however some paints are made with two or more pigments. The more pigments there are in a paint the harder it is to mix it and achieve vibrant colour mixes. However paints that are made with multiple pigments are done so to meet artist demands. Usually to offer popular colours that can be used straight from the tube without need for any pre mixing.<\/p>\n

The speed and duration of the mixing time will depend on the characteristics of the pigment, such as particle size and absorbency. Once the pigment is thoroughly dispersed throughout the oil it is then transferred to the milling device. Milling involves putting the paint through three spinning metal cylinders which will help refine the mix – removing any \u2018clumps\u2019 of pigment particles to even out the consistency even further. Again, the speed at which the cylinders spin, the amount of pressure, and how long the paint is milled for is all part of the recipe for each specific pigment. Each has a different requirement. Milling can take anything from hours to days depending on the colour.<\/p>\n

Testing<\/h2>\n

The batch of paint is then tested before it is packaged in tubes. First of all a spread test is conducted. This involves placing a specific amount of paint between two pieces of glass which are then squeezed together using a brass weight. If the blob of paint does not spread far enough then it is likely that the paint will need more milling. Secondly a dispersion test is conducted: A specific amount of paint is spread across a metal gauge which measures the size of the pigment particles; if they are too large then the paint will require more milling. <\/p>\n

The final test is the drying test. Each colour has a known drying time (anything ranging from two days to two weeks). So, an amount of the paint is applied to a surface and assessed regularly by a technician to make sure it is drying as it should. If the paint passes these tests it is finally poured into metal tubes which are then labelled and ready to be distributed to art shops.<\/p>\n

Other Ingredients<\/h2>\n

On occasion there are other ingredients in your tube of oil paint.<\/p>\n

Beeswax<\/b> is added to help the pigment stick to the drying oil and also help prevent the pigment from sinking to the bottom of the tube.<\/p>\n

Driers<\/b> are added to help speed the curing process. Although most professional ranges avoid driers as they can impair the strength of the paint film.<\/p>\n

Alkyd resin<\/b> is sometimes added to add lustre and speed drying of the paint.\n<\/div>\n

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Drying Oils<\/h2>\n

A drying oil is a natural oil that oxidises when exposed to air,\u00a0causing it to contract and harden into a solid layer. Linseed oil is the most common drying oil used in oil paint manufacture; however Poppy, Walnut and Safflower are all used as well. Each oil brings its own characteristics to the personality of the paint.<\/p>\n

Linseed Oil<\/strong> is essentially the same as the flaxseed oil you might come across in your local supermarket, but it is not edible! The extraction methods used for artist\u2019s linseed oil use petroleum which makes it only really suited for art purposes. Conversely flaxseed oil will have impurities in it that will cause a greater degree of yellowing over time. Linseed oil dries very thoroughly and so creates very stable paint. <\/p>\n

Both Refined Linseed Oil<\/strong> and Cold-pressed Linseed Oil<\/strong> are known to be used in oil paint manufacture. Which is superior is a case of personal preference. While cold pressed linseed oil has not undergone any chemical treatment and so is therefore often considered the more stable of the two varieties of oil, refined linseed oil is likely to have less impurities and so will have less tendency to yellow over time. Ultimately you can get varying qualities of both, but what paint manufacturers (and possibly you!) will look for is an oil with the least impurities. These oils will look clearest in the bottle.<\/p>\n

Poppy Oil<\/strong> is a very pale, more transparent drying oil that is less likely to yellow than linseed oil. It is much slower drying than linseed oil – on average 5-7 days – which makes it ideal to use when working wet-into-wet. At one time Poppy oil was used in the manufacture of some whites but more recently the use of less expensive Safflower oil has become more common.<\/p>\n

Walnut Oil<\/strong> has been used to make oil paint for longer than linseed oil and again is used to make whites on occasion, as it yellows less than linseed oil. As a result, paler and cooler colours suffer less change as they dry. The film of walnut oil when dry is stronger than poppy oil (though still not as strong as linseed). This makes it a better oil to use in the initial layers of paint. It is a great oil to use when painting detail and it has a similar drying time to linseed oil. Walnut oil paints have a rich, silken texture with refined handling which is thought to have helped Baroque painters achieve wonderful effects when painting the ruffs of collars and other detail in opulent clothing.<\/p>\n

Safflower Oil<\/strong> is also used to make whites in some brands because it is bright and clean with less tendency to yellow than linseed oil. It takes 2-3 days longer to dry than linseed so is recommended only for use in the final layers of a painting.\n<\/div>\n

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The difference between thinning and extending paint: Note the difference in appearance between adding solvent (middle) and adding linseed oil (right)<\/figcaption><\/figure>\n
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How Oil Paints Dry and the Fat Over Lean Rule<\/h2>\n

Oils can be extended with drying oils and thinned with solvent. The drying process is different to other paints; acrylics and watercolours dry as their water content evaporates into the atmosphere, while the oil in oil paint reacts with air causing it to solidify. This process is called oxidisation. In the meantime, the solvent in the paint evaporates. While the evaporation of the solvent doesn\u2019t take very long at all, the oxidisation process is very slow and never really stops. As oil paint oxidises it also contracts. If anything that dries faster is put on top of not-sufficiently-dry oil paint it is likely to crack. <\/p>\n

This explains why oils can only be painted over acrylics but never the other way around, and why oils should always be painted fat over lean: the more oil (or fat) in the paint the longer it will take to dry. Always put paint with more oil over the top of paint that has less oil in it (more diluted with solvent).\n<\/p><\/div>\n

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What is the Difference Between Traditional Oils, Water-Mixable Oils, Alkyd Oils and Oil Sticks?<\/h2>\n

Traditional oil paints<\/strong><\/a> are made using finely ground pigment particles suspended in drying oils, usually linseed but sometimes pale colours are mixed with poppy, safflower or walnut. The buttery consistency can be made more fluid by whipping the paint up with a palette knife once squeezed from the tube. Transparency, sheen, drying times and thickness can all be altered by adding mediums, available pre-mixed or made using drying oils and solvents.<\/p>\n

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A range of brush marks all made using the same paint – a range of tones can be achieved just by thinning a little with solvent or adding a little extra oil.<\/figcaption><\/figure>\n

Water-mixable oil paints<\/strong><\/a> offer the charm of traditional oils with the added advantage of not requiring solvents for either thinning or the clean up operation. Water-mixable oils can be a little more stringy or fluid than regular oils, but for many the advantages vastly outweigh the disadvantages. There is no need for the heady fumes of solvents, and a much safer and easier clean-up operation with soap and water. Special water-mixable oil painting mediums are also available. It\u2019s possible to mix water-mixable oils with regular oils but in doing so they lose their water-solubility.<\/p>\n

Alkyd oil paints<\/strong><\/a> contain the same alkyd resin used in painting mediums to speed drying; a godsend for painters who have little time to spare.<\/p>\n

Oil bars<\/strong><\/a> are also known as pigment sticks and are a mixture of pigment, oil and wax. Use them to draw straight onto canvas – a direct, tactile and expressive way of working. Marks can be thinned or made more fluid with solvent and oils, just like regular oils.<\/p>\n

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Oil Sticks are real oil paint mixed with a small amount of wax to form a stick. Because the part exposed to air will dry like any oil paint you will need to peel the dried skin of oil paint off the end and then you can draw with paint. Or thin it or extend it just as you would with regular traditional oil paint.<\/figcaption><\/figure>\n<\/div>\n

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Which Brand?<\/h2>\n

All brands of oil colour are intermixable. Traditional oil paints are classified as being either \u2018Professional\u2019, \u2018Artist\u2019 or \u2018Student\u2019 quality, with a couple of exceptions that straddle these classifications. Price and the name of the range usually indicate the paint\u2019s quality.<\/p>\n

Professional<\/b> paints<\/b><\/a> pack in as much pigment into the oil as possible. Pigments are ground to a precise particle size that optimises the visual qualities of the colour, and then milled carefully into the drying oil binder. Occasionally the pigment to oil ratio is so great that the weight of the pigment sinks to the bottom of the tube. This causes the binder and pigment to separate (this can be rectified by stirring the contents of the tube with a straightened paper clip). This allows the unique characteristics of the pigments to have a greater influence on the behaviour of the paint – properties such as sheen, transparency, tinting and staining capacity. These vary from colour to colour and contribute to the dynamism that can be achieved on your canvas. <\/p>\n

Professional paints comprise a greater number of single pigment colours; colours look purer, more luminous and are easier to create vibrant mixes with. On the website paints that are\u00a0classified as\u00a0‘Exceptional’ at jacksonsart.com<\/a>\u00a0are generally considered Professional quality.<\/p>\n

Artist quality paints<\/b><\/a> have a little less pigment in the mix but are usually made using very similar processes as professional paint. The characteristics of each pigment are maintained but with less intensity than the professional paints. Paints that are classified as ‘excellent’, at jacksonsart.com<\/a> are considered Artist quality.<\/p>\n

Student quality paints<\/b><\/a> have less pigment in them in order to keep production costs down. And may have added fillers to make the paints more uniform in tinting strength, viscosity and covering power. Driers are often added to slow drying pigments so that all colours dry at the same rate. The differing drying times of colours in professional and artist ranges can be a surprise for painters that have upgraded from student paints. <\/p>\n

Combinations of less expensive pigments are sometimes blended to replace the most expensive single pigment colours (these have the word \u2018hue\u2019 in their colour name). Colours may appear more chalky than Artist and Professional colours, and the choice is sometimes more limited and conventional. However, the affordability of student grade paints make them a popular choice for painters who are new to oils as well as those who need to stick to a budget. Paints that are classified as ‘good’ at jacksonsart.com<\/a> are considered Student quality.<\/p>\n

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Same Colour Name, Different Colour<\/h2>\n

It\u2019s worth noting that paints with the same colour name but made by different manufacturers may look different. This can be down to different pigments being used or differences in production methods. One brand may use different binders or fillers to another brand, and they may mill the paint differently too. Most oil paints (and certainly professional and artist grade brands) will list the pigment codes on their label. But again, if there are multiple pigments in the paint there is no guarantee that the quantities of each pigment will be the same in the different tubes. Ensuring the pigment codes match may not guarantee that the paint will look the same as it is squeezed out, but at least how the paints mix with other colours will be similar. <\/p>\n

Finally, colours may even have subtle differences within the same brand. Colours are made in batches and although manufacturers will try to match batches with what’s been made before as much as possible, if the pigment itself is slightly different (maybe as a result of being sourced from another location) then this will result in subtle differences in the batches of paint produced. If colour matching is of absolutely vital importance (as it would be if you were a picture restorer or if you were painting a highly detailed work) then we would always suggest you test the appearance of the paint on a separate panel prior to using it on your work in progress.\n<\/p><\/div>\n

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What Mediums Do I Need?<\/h2>\n

There are more oil paint mediums on the market today than ever, giving you the opportunity to work with paint that has the exact qualities that you\u2019re after. Here\u2019s what you can do to modify your paint with oil mediums:<\/p>\n

Increase Transparency<\/h2>\n

All mediums extend colour and therefore increase transparency. If you\u2019re looking to keep the drying times nice and slow to allow for blending, add a little drying oil such as linseed<\/b><\/a>, stand<\/a>, poppy<\/a>, walnut<\/a> or safflower oil<\/a><\/b>. The more you add and the thicker you apply it the longer the drying time, which can be anything from overnight to months. If it\u2019s too thick there\u2019s a risk of the top layer wrinkling, caused by the paint on the surface contracting at a faster rate than what\u2019s underneath. <\/p>\n

Linseed oil<\/b><\/a> is amber coloured and pourable like double cream, Stand oil<\/b><\/a> is linseed oil that has been thickened through a special heating process, and is particularly treacle-like in colour and consistency. It\u2019s very useful in glaze mediums. All varieties of linseed oil will give a yellow tint to pale mixes. Poppy<\/b> <\/a>and Safflower oils<\/b><\/a> are both much paler than linseed oils and are often added to pale colours as they hardly tint colour at all, but they do tend to take even longer to dry. <\/p>\n

Walnut<\/b><\/a> is also used with paler colours, and is faster drying than poppy or safflower. It dries with a more flexible paint film which means it\u2019s great to use if you are layering colours. \u00a0Alkyd resin mediums, <\/b>such as Liquin <\/b><\/a>or Jackson\u2019s Fast Drying Oil Painting Medium <\/b><\/a>will speed drying. <\/p>\n

Glazing<\/h2>\n

Glaze mediums are specially formulated to increase transparency and gloss for glazes that layer beautifully. \u00a0Solvents such as turpentine<\/b><\/a> or Zest-It<\/b><\/a> dilute rather than extend paint, so add a little of either to your medium to stop your paint becoming too gloopy. Household white spirit is too abrasive, can kill the vibrancy of paint and is not recommended for oil paint mediums. Remember too that some colours are naturally more transparent than others and that nearly all colour charts will specify the transparency of each colour in their range.<\/p>\n

Alter sheen<\/h2>\n

When used neat, oils usually dry with a subtle velvet sheen. Adding one of the drying oils or an alkyd medium such as Jackson\u2019s Fast Drying Oil Painting Medium<\/b><\/a> will increase gloss. For high gloss glazes try adding a small quantity of Dammar<\/b><\/a> or retouching varnish<\/b><\/a> to your medium, or try our pre-mixed Jackson\u2019s Glaze Medium<\/b><\/a>. Beeswax<\/b><\/a> mediums will reduce or keep gloss at the original level of the paint. Adding a little more artist\u2019s solvent to mediums will also help to bring down the shininess!<\/p>\n

Alter drying time<\/h2>\n

Drying oils (linseed<\/a>, stand<\/a>, walnut<\/a>, poppy<\/a>, safflower<\/a>)<\/b> will slow drying times, while alkyd<\/b> mediums (Liquin<\/a>, Galkyd mediums<\/a> and any fast drying oil painting mediums<\/a>), artist\u2019s solvent<\/a><\/b> (turpentine<\/a>, Zest-it<\/a>, Shellsol<\/a>, Gamsol<\/a>, Sansodor<\/a>, oil of spike lavender<\/a>)<\/b> and driers such as cobalt (found in siccative<\/b><\/a>) will speed drying. <\/p>\n

Many oil painting mediums available are made of a mixture of solvent, oil and resin. They are designed to subtly increase gloss, give a workable consistency, and dry faster than neat oil paint. It\u2019s possible to alter pre-mixed mediums – reduce sheen and speed drying times by adding a few more drops of solvent<\/b>, or increase gloss by adding a bit more oil<\/b>. You can also make your own mediums by combining drying oils with solvents. A couple of drops of siccative<\/b><\/a>, dammar<\/b><\/a> or retouching varnish<\/b><\/a> all speed drying and increase gloss when added to painting mediums. <\/p>\n

Siccative should only be added in very small quantities (10% of the paint mixture) to ensure that the paint doesn\u2019t dry so fast that it cracks. And it\u2019s best to avoid mixing so much solvent into your paint that it forms the majority of the overall recipe. This is because it breaks the paint down and very dilute layers of oil paint are much more fragile as there is not enough oil to harden to a firm layer.<\/p>\n

Thicken or thin the paint<\/h2>\n

Make your oils pourable by adding linseed oil<\/b><\/a> and solvent <\/b><\/a>in near equal measure (a touch more oil than solvent). If you want your oil paint to have a treacle texture and gloss try adding stand oil<\/b><\/a>. <\/p>\n

Liquin Impasto<\/b><\/a> or beeswax <\/a>based mediums<\/b> will thicken the paint even further without layers wrinkling or taking a lifetime to dry. To learn more about how to thicken or thin your paint it pays to try a little bit of this and a little bit of that – add a little solvent, a little oil, try more or less paint in the mix\u2026 so long as you stick to the \u2018fat over lean\u2019 rule (always apply mixtures with more oil in them on top) you can\u2019t really go wrong.\n<\/div>\n

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Gloss, Satin and Matt Varnish<\/figcaption><\/figure>\n

Varnish<\/h2>\n

Solvent-based varnishes will alter sheen and protect oil paintings. Varnish is made of natural or synthetic resin crystals dissolved in solvent. There are two main types of varnish.<\/p>\n