Traditional Oil Paint is a variety of a slow-drying paint made up of particles of pigment suspended in a drying oil that on exposure to air forms a tough, bright, rich coloured film. The advantage of the slow-drying quality of oil paint is that an artist can develop a painting gradually, making changes or corrections if necessary.
Oil paint is popular a popular choice as its translucence, sheen, drying time and thickness can all be adjusted with the use of mediums, waxes, resins, and varnishes.
Typically the drying oil used in paint manufacture is a vegetable oil, with linseed oil the most commonly used, but for paler colours other oils such as safflower, walnut or poppy oil are employed instead.
Oil paints blend well with each other, making subtle variations of colour possible as well as more easily creating details of light and shadow. It is possible to mix various brands and qualities of oil paint.
Oil Paints are available in a large range of costs, brands and qualities.
‘Artist’ or ‘Professional’, brands like Winsor & Newton (W&N) Artists Oils or Michael Harding, are quality paints that offer a larger colour range and use the best quality pigments, which is why they are split into ‘series’ that reflects the cost of the raw materials, such as pigment, used to make it. They will also tend to use the most suitable drying oil dependant on the shade.
‘Student’ quality oils, brands such as W&N Winton, or Daler Rowney’s Georgian, use either less pigment and more fillers or a synthetic version of a natural pigment (normally indicated as ‘hue’ on labelling) and as a result are priced at a standard price across the range and typically offer less colour choices. As well as being popular for people starting out they are also ideal to use for base or for under painting where large quantities of colour are required, but is likely to be covered up.
Oils can be diluted with turpentine and other thinning agents and mediums to create different effects. A layer that has been heavily diluted will dry relatively quickly, being tack-free in a few days. Thicker layers, containing more oil, will take longer. Oil paint continues to dry, getting harder with age over many decades. Pigments and extenders will also affect the rate of drying, so different colours may dry at different speeds.
Other types of Oil Paints
Faster drying Alkyd Oil Paints, e.g. W&N Griffin range, offers a fast drying option, typically surface dry in 18 to 24 hours, using unsurprisingly an alkyd resin (also available as a medium for traditional oils) rather than the traditional vegetable oil drying oils. It is not uncommon to use both Alkyds and traditional Oils together, either using the Alkyd as a base layer, or mixing them together to speed up drying times.
Water-mixable or water soluble Oil Paints, for example W&N Artisan, these paints offer an alternative to traditional oil paint with its long drying times and sometimes harsh fumes from solvents that are used, water-mixable paints also suit people with allergies to traditional solvents and people who work at home, in confined spaces or with children.
They aren’t water based, but instead made with oils that have been formulated to mix with water. Traditional linseed oil can be used to thin water soluble oils and will give the painting a nice sheen and add depth to the colour. There are also other specially formulated oils, mediums and blenders available designed to work with these non-traditional oils.
Water-mixable oil paint has a lot in common with the way traditional oils are used and many people actually prefer them.
Oil Bars/ Oil Sticks, including W&N brand or Markal Paint Sticks, are made of the same pigments and drying oils used in tube oils. The paint is then combined with wax and rolled into a crayon, basically Oil Paint in a solid form. Different to oil pastels, Oil Bars form a skin as the oil dries. When this top layer of paint solidifies, it seals the wet paint in underneath, much like oil paint.
Oil Bars are used for drawing directly on to a surface, combine with oil paints and mediums and are ideal for multimedia work.
Put simply a medium is an additive to paint formulated to affect the paints performance, either to enhance by creating effects such as a lustre or translucency or to change its characteristics such as a drying time.
Gesso Primer-is in fact an acrylic medium. However, it's widely used as a base coat for art surfaces when oil painting.
Turpentine or ‘Turps’ is the best known thinner and cleaner for oil paints and brushes.
Artists Turpentine is distilled, unlike the household version and so provides the best finish on your painting. However, its powerful odour is not always welcome and may be an irritant for some artists.
Low Odour Thinners, such as Sansodor or Zest-it, are an excellent substitute for turpentine
Linseed Oil, slows down drying time, on its own gives colours a high gloss and added to colours it produces a glaze effect. The glazing technique is where a translucent colour is painted over another, dried colour, ideal for creating misty or smoky backgrounds, the lower layer glows through, by how much is affected by the density of the top glaze.
Used 50/50 with turpentine or low odour thinners, it provides a good, general purpose paint medium for oil painting. It can go a little more yellow than other oils over a period of time.
White Spirit is a cheaper version of turpentine and low odour thinners, it is OK for thinning paints for underpainting, but not really suitable for quality work. Popular for cleaning brushes.
Prepared Oil Painting Mediums vary from one manufacturer to another, often they are a combination of white spirit and other oils to provide a ready-mixed, user-friendly paint diluent, ideal for beginners, rather than trying to mix their own combination of oils and other additives.
Stand Oil is a faster-drying version of linseed oil, reduces brush marks and consistency of paint.
Poppy Oil is for adding to lighter colours and whites. Less inclined to yellow than linseed oil but is slower drying.
Gold Size, although primarily intended for applying gold leaf, it provides a relatively fast drying oil-based paint medium.
Alkyd Gel & Liquid Oil Painting Mediums. Alkyd paint mediums can be added to conventional oil paints to speed drying time by up to 50% and can also be used as a glazing medium.
White Alkyd Paint, not strictly speaking a paint medium, but can be used speed the drying of conventional oils where a lighter tint or a highlight is preferred rather than a glaze. The white alkyd paint, when mixed with other colours, acts in the same way as the alkyd gel, but doesn't lose the opacity.
Picture Varnish, available in Matt Gloss or Satin finish are spirit based varnishes in liquid or aerosol sprays, that can be used on acrylics as well as oils drying without yellowing or blooming. Can be removed with turpentine or white spirit.
Retouching Varnish is a thin varnish which can be painted over a touch-dry painting to 'lift' dull spots, areas where the oil has sunk into the surface. It can also be used as a temporary varnish, say for exhibitions, where thicker paint on a recently completed painting may take many months to dry through completely. Can be removed prior to, or left on underneath, the final varnish coat.
Dammar Varnish dries in a few hours with a satin/medium gloss and is removable.
Oil painting brushes come in a variety of types and sizes, they are firm and don’t bend too sharply over the ferrule. Hog Hair brushes are the traditional choice, but Synthetic brushes specifically designed for use with oils and Acrylic paints are commonplace and dependant on style or technique it is not unusual to use brushes designed for other mediums such as watercolour, although oil paint and it’s surfaces by its nature is very harsh and will render these types of brushes unusable in a short time.
Long handled brushes, allow the painter to work at a further distance from the canvas, making it easier to see the painting develop, short handled brushes typically are used for more detailed work.
Types of brushes
Round brushes- Versatile and can be used for almost any purpose during painting.
Flat brushes- are often used when applying large areas of colour.
Filberts- Used to soften edges
Brights- Short flat brushes, ideal for adding texture the surface of a painting for bold impasto effects.
Fan brushes- Use to feather away brushstrokes and soften tone gradations.
Palette and Painting knives
An alternative to brushes for applying paint to the painting surface or used for mixing or cleaning colours from the palette, like brushes they are available in a wide variety of shapes and sizes, with both tools available made of either of wood and metal or plastic. Though the terms are interchangeable a palette knife handle is generally straight, having at most a slight bend, the purpose of which is to mix colours or clean the surface of the palette, whereas a Painting Knife has a deep bend in the handle designed to keep the artist’s knuckles out of the paint while applying it.
A Palette is a flat, non-porous surface, such as treated wood, melamine, plastic/acrylic, safety glass or pads of disposable paper, used to mix colours or on to which a selection of premixed colours can be squeezed out to allow the artist speedier access. The palette can be placed on a nearby surface or more typically hand held using palettes designed for that purpose that have thumb holes. Available either oblong or oval in shape, often selected by personal preference.
A wooden palette is normally coated with linseed oil and will be wiped dry before its daily use. At the end of a session the palette should be cleaned re-coated with linseed oil and wiped dry again.
Clear palettes often require a neutral colour backing, by taping paper to the back of them, mixing colours on a white background can make it hard to distinguish dark colours and vice versa.
All palettes should be cleaned after use, a glass palette has the advantage of being able to be cleaned using a blade edge.
Most surfaces used are primed or manufactured to allow the oil paints to sit on the surface, un-primed canvas is available for the artist to prime themselves either using traditional methods such as size & whiting but most common is Gesso an Acrylic based primer, which the majority of prepared surfaces use.
Canvas is the traditional choice, stretched over a wooden frame. Linen, used by the old masters, offers an irregular surface or primed with a clear primer provides a natural, warm background choice and is typically more expensive than the most commonly used canvas Cotton, which provides a more regular surface.
Alternatively canvas is available mounted on a board rather than wooden stretcher bars, offering the same surface at a lower cost and is also ideal for taking sketching outdoors, or there are paper products such as Daler Boards and oil painting paper available in sheets or pads. Another traditional surface are Wooden boards, available either pre-primed or as with many other surfaces be primed by the user using Gesso primer.
If priming your own surface Gesso is also available in a wide range of prices and brands, typically white, although available clear or black or it can be tinted with acrylic paints or its texture changed using mediums to suit the artists desired effect.