Beginners to oil painting tend to find the rules and methods behind oil painting technique to be more than a little confusing. Some pick up the medium and use techniques that are familiar to them from other creative disciplines. However, oil painting has a long and developed history and there are sets of rules that have been established to guarantee that your painting will be sucessful every time. Learn more about these oil painting rules below, and master them to consign cracked and crazed oil paintings to the past!
Due to the oil content of oil paints, and the effect this has on drying rate, there are a set of rules to follow to ensure that you don't get caught out by some of the common pitfalls of oil painting. Most oil painters will build up their paintings in successive layers, with the content of each layer carefully considered. By wrapping your head round these oil painting rules you can minimize the chances of running into complications and problems.
If you're just starting out with oil painting then this term may quickly become something that you are sick of hearing. It is perhaps the single most important and most-repeated principle when describing the process of builing up your oil painting in layers. If you choose to paint in layers you must always ensure that each subsequent layer contains more fat than the last. Layers with a higher fat content (i.e. more oil) will take longer to dry, whereas leaner layers (i.e. less flat) will dry much more quickly. If a lean layer is applied over a fatty layer, the lean layer will cure much more quickly. As the fatty layer continues to dry underneath it will contract and cause the lean layer above to move and crack. If you leave each layer to cure fully before painting newer layers then you will not need to abide by this rule.
As you build your painting in layers it is important that each additional layer is thicker than the last. In a similar manner to the 'fat over lean' rule, if a thin layer is added over a thick layer you will find that the top layer is much quicker to dry than the bottom. This difference in drying time will cause the thin layer to crack as the thicket, bottom layer contracts as it dries. It is always advisable that thicker layers are applied alone, or over a thinner underlayer to ensure that the thick layer is able to dry.
The drying time of your paints will vary depending on the oil content of the paint and also the mediums and solvents that it is mixed with. The differences in drying times occur due to the different reactions of each pigment when dispersed in oil. Some pigments behave like catalysts, speeding up the drying process. Others have little effect if any, and some slow the process. Slow drying underlayers can cause cracking of any susequent faster drying layers. In general, you should avoid creating thick, continuous layers of slow drying colours in any underpainting.
The Oil Painting world is peppered with terms that refer to the different types of techniques artists' commonly employ. You may have even used some of these techniques without realising it! This list is certainly not exhaustive, but includes some of the more popular terms that you may hear bandied about during your oil painting sessions!
Alla Prima refers to paintings that are completed in one painting session. The direct translation of this Italian term means 'all at once'. Generally the paint is added in one application, although there is some debate about whether areas may be removed or reworked.
This term refers to paintings that have a pronounced contrasts between dark and light. These strong tonal contrasts create dramatic forms that appear three-dimensional. Notable employers of this technique include Da Vinci, Carravagio and Rembrandt.
Colour mixing is a technique that is used to create the largest number of options from the minimum amount of colours. Some artists choose to use colour straight from the tube, but a greater tonal range can be achieved through mixing your own colour.
Glazing is the process of building up transparent layers of paint over dry underlayers. This technique is great for unifying tone and creating luminosity. It is generally achieved through the use of Blending and Glazing Medium, Liquin or Stand Oil. Griffin Alkyds are ideal for creating glazes as they have transparent, luminous colour.
Grisaille refers to a painting that is painted in a monochrome colour scheme. These colour schemes are comprised of one colour, and tonal range is created with the addition of white paint. This technique is great for creating an underpainting to establish tonal range in your painting. Artists commonly apply transparent glazes over the top of grisaille works to add colour.
Impasto refers to paint that is applied thickly to your paper, board or canvas. This thick, stiff colour retains the brush and knife marks which can introduce texture and create a dynamic, powerful painting. Impasto paintings are usually developed in layers, although you must ensure that the last layer is dry before applying the next. Oleopasto can be used for impasto techniques, but has the added benefit of being quick drying.
Sometimes areas of your oil painting may become dull, usually caused by oil being lost from the top layer to the layers below. Oiling out is theprocss of bringing back that sheen. This can be done by sparingly rubbing Winsor & Newton Artists' Painting Medium using a cloth. Wipe off any residue and leave the painting to dry for a day or two. If smaller, dull areas remain, repeat the process until the painting has regained an even sheen. Varnishes should not be used for the purpose of recovering the lustre of a dead painting. For a faster drying oiling out medium, use Thickened Linseed Oil diluted with 50% white spirit (mineral spirits). Absorbent grounds are notorious as a cause for sinking. Overthinning colour with solvent can also be a cause.
Plein Air is the process of painting outdoors. Painters commonly gather their supplies in a caddy, pochade box or other container and position themselves in front of their subject ready to paint.
Is the process of working with a stff brush to add a thin flm of opaque or semi-opaque colour loosely over your painting, allowing colour from below to show through. This technique is great for adding texture and depth to your artwork.
Sfumato is a technique that involves painting in thin glazes to gradually allow tones and colours to blend together. The result is a smokey, misty effect that can create perspective and atmosphere.
S'graffito is the process of scraping into a wet oil film, most commonly with the end of a paintbrush or the edge of a painting knife. Great for defining edges, it can also be used to create expressive marks.
The first layer of paint applied to your canvas is known as the underpainting. Underpaintings are great for establishing tonal range and mapping out your general composition. It is important that underpaintings are created using lean, quick-drying colours; this will lessen the chance of cracking as subsequent layers are added.
Usually a traditional glaze is made by using transparent pigments to create a thin film of colour. A Velatura glaze is one created using a semi-opaque to form a milky, translucent glaze. These types of glazes allow traces of detail and colour beneath to show through.
This technique involves adding fresh layers of colour to paint that is still wet. This technique is ideal for blending and can be accomplished with colour in virtually any state of viscosity from thick and stiff to fluid.