Oil paints - characteristics

History

Oil paints in various forms came into use in the fourteenth century. The rise in their popularity and the development of oil painting, in turn, dates to the fifteenth century. Prior to their appearance, artists usually resorted to tempera medium composed of mixed pigment and egg. Oil paints displaced tempera over time, and were helped by their far superior qualities: unheard-of versatility and flexibility, richness of color, subtlety of expression, and longer drying times, which allowed painters to mix paints together and correct them with greater precision. The gentle, impeccably modeled forms characteristic of Renaissance art probably would not have been possible without the use of oil painting and the realization of its artistic potential.... Initially, the preparation and manufacture of oil painting was carried out in the painting studio by the apprentices who practiced there. Toward the end of the 19th century, paint studios began to appear in Europe, offering media that had already undergone pre-treatment, including pre-painting. While oil painting has undergone various stages of development and improvement throughout history, there is no doubt that the products offered to painters today are vastly superior in quality to those available centuries, generations, or even decades ago. Why? New, more durable materials, technologically advanced manufacturing processes, as well as the expertise and experience of manufacturers accumulated over the years have resulted in paints whose quality is able to meet even the most sophisticated needs of today's painters.

Ingredients

Today, traditional oil paints are obtained by essentially the same manufacturing processes used in the 15th century. The pigment is mixed with a carrier liquid in the form of linseed oil (extracted from flax) and sometimes safflower oil (which is lighter and dries more slowly). Instead of grinding each paint by hand using a stone (marble) or glass slab and a glass pestle, top-quality paints are obtained today using a variety of technological grinding methods. Depending on the individual nature of each pigment and its properties, a decision is made as to the length of the grinding (the number of passes in the mixer with a triple roller mill), the amount of oil used, as well as its type.

Characteristics of oil paints

The finest oil paints are characterized by:
Depth of color - the depth effect will be ensured by proper mixing of linseed oil with a high concentration of pigment. Such treatment will consequently translate into the coloring power of the paint, its ability to combine with other paints and the ability to take full advantage of the transparency and covering power of each pigment. In addition, the refractive properties of the oil (the way the light penetrating the carrier liquid refracts) will consequently give a richness of hue, depth and freshness in the likeness of a precious stone - parameters unmatched by any other medium.

Extended processing time - depending on the type of pigment, oils are characterized by drying times in the range of 2 to 12 days. This gives the artist the opportunity to mix paints for longer periods of time, modeling and improving the paint job. The differences in drying times are due to the different chemical reactions in the process of blending the various pigments with the oil.

Stability and durability in the tube - a properly carried out blending process ensures that the paint remains in the tube unchanged for a very long time. Paints grated with less care tend to delaminate, with the oil accumulating at the top of the tube, leaving the pigment content at the bottom. In addition to the obvious inconvenience to the artist caused by this kind of reaction, delamination can also lead to a situation where the paint is unable to bind to the substrate due to insufficient oil.

Durability and stability on the painting surface - top-quality oil paints are an ideal combination of pigment and binder, which allows the oil to dry in a way that creates a stable, uniform coating that can last for many years under the right conditions.

A few words about paint drying and color film stability

In the case of linseed oil, the drying process is caused by oxidation, a chemical process that occurs when oxygen in the air combines with the oily paint film. In short, oil paint dries in a long and slow "breathing" process. The drying mechanism begins when oxygen binds to the oil molecule, giving rise to a reaction that transforms the essentially linear structure of liquid oil into a hard, three-dimensional crystalline structure. A properly applied oil coating can be very stable and durable. However, anything that can interfere with the drying or polymerization process - as a result of over-thinning the paint or using insufficiently purified solvents - can result in a color coating that is less able to resist the damaging effects of time. The following section includes information on how to use oil painting in a way that will provide the greatest possible durability. However, it is generally accepted that in order to achieve a durable color coating, four basic rules of conventional oil painting should be followed:

Avoid adding too much solvent to the paint mixture - excessive solvent dilutes the chemical structure of the paint, preventing the paint from bonding to the painting surface and forming a structural coating.

Always use cleaned high-quality solvents - solvents of your own making, or those that have not been properly cleaned, contain impurities that will adversely affect the formation of the structural color film.

Do not use old or already oxidized turpentine - to ensure the freshness of turpentine and its usefulness in the painting studio, it should always be stored in hermetically sealed bottles, in a dark place. Turpentine that has oxidized leaves a sticky residue that can prevent paint from drying.

Observe the principles of "fat on thin" and "thick on thin" - These techniques ensure that the paint layers applied in succession are more pliable, making them less prone to cracking.