1. PREPARING THE GROUND
The quality of the formulation largely determines the eventual lastingness of the artwork. Paper, cardboard, wood, cotton and linen can be used as grounds for vegetable oil paint, but not without prior treatment. An untreated or insufficiently treated ground will suck the anoint out of the paint and will finally be damaged by the petroleum. A key layer must contain sufficient oil in orderliness to surround the pigments and form a good film. only then will the pigments be sufficiently bonded and premature cleave and crack up avoided .
Gesso is used to ensure a good preparation
Talens Gesso is made using a pure acrylic resin and is of superlative quality. Produced according to a special convention, gesso performs the functions of the assorted layers. The layer, however, must be midst enough, and so it is best to apply this in two goes. For the first layer the gesso can be thinned with water to an easily spreadable thickness. Next a second layer is applied, pure or slenderly thinned with water .
For highly absorbent grounds the ground first can be treated with a layer of Amsterdam Acrylic binder, a pure unpigmented acrylic resin. The gesso can then be applied, preferably criss-cross in two ( slightly thinned ) layers.
Talens stretched canvases, roll poll and sail boards have already been prepared.
2. APPLYING THE PAINT
There are in hypothesis two petroleum painting techniques : ‘ alla leading ’ and ‘ layered painting ’ .
Alla prima
Alla leading refers to the paint being painted ‘ wet-into-wet ’. With this technique the colours are assorted not entirely on the pallette, but besides in the painting itself, applied wet aboard and over one another. The painting, which is ultimately built up of a single layer, must be completed while the paint is calm wet. The paint can be applied pure or combined with always the lapp medium or solvent .
Layered painting
With layer painting the painting is built up of versatile layers. A future layer can only be applied once the previous layer is dry enough to ensure that it will decidedly not dissolve. With layered painting a technique has to be followed that is known as ‘ fat over lean ’ ; every subsequent level has to contain more petroleum .
You can not always foresee precisely how many layers are needed to come to a satisfactory leave. guarantee, therefore, that the paint is never besides fat so that any subsequent paint layer is still able to bond. pure oil as a medium is surely not advisable ; the key can then become excessively plastered resulting in a subsequent layer not being able to alliance well. What ’ s more, with excessively much oil there is a greater hazard of furrow of the paint film during the dry process .
Fat over lean
Ensure the first layer is applied lean. To this end the paint has to be thinned with white spirit or turpentine. While this layer dries it will not produce a seal rouge film, but a porous one. oil from a subsequent layer will be absorbed by the fundamental list layer and secure itself in the numerous pores while drying. This will produce dear adhesion between the two layers. As an underlie ( lean ) level draw oil from the layer above, you have to ensure during painting that the layer above contains relatively more anoint. If this is not the case, quality problems can arise .
The attachment of the paint layers and the ‘ fatty over lean ’ principle together besides ensure that the tension between the diverse rouge layers is absorbed. A painting is constantly exposed to motion – on the one pass by the flexibility of the grounds such as stretch analyze, and due to fluctuations in temperature and humidity on the other. To ensure the lastingness of the paint it is therefore authoritative that all key layers can absorb these movements .
The more oil a paint level contains, the more elastic it will be once it is dry. If a painting were to consist of respective layers whereby the lower layers contain more anoint than the final layers, therefore against the ‘ fatness over thin ’ rule, the less elastic exceed layers would then in due course be torn apart by the moving layers underneath When this becomes visible, it is referred to as cracking. Cracking can be avoided by making every subsequent layer a little fat. ‘ Fat over list ’ can therefore besides be interpreted as ‘ elastic over less rubber band ’. This makes it immediately clearly why a rouge layer needs to dry sufficiently before applying the following layer. A layer that has not dried sufficiently is often besides elastic for a following level. And that can besides cause cracks to form .
It is of class up to the artist how many layers are applied when building up a paint. It is advisable though to thin the paint with white emotional state or turpentine for the first layer. The more solvent, the lean the paint layer. When the first layer is dry enough the second rouge layer can be applied. From this degree there are respective ways forward :
- Thin every subsequent layer with a decreasing amount of solvent; each subsequent layer therefore has to contain relatively more oil. This process can eventually be finished with pure paint.
- Mix the paint for the subsequent layer with a painting medium. A good medium consists of three components: oil, resin and solvent. The oil makes the paint fatter, whilst the solvent ensures that the paint does not become too fat. The resin as third ingredient increases the durability of the paint layer.
- If a painting is built up in more than two layers, the medium can be mixed proportionally with white spirit or turpentine from lean to increasingly fatter. The larger the relative amount of medium, the fatter the mixture. For the final layer the paint can be mixed with pure medium.
Besides the pigments used, the binder ensures for some important properties. Linseed oil has throughout the centuries shown itself to have the best combination of properties. As linseed vegetable oil shows some yellow in time, it is sometimes replaced by safflower oil particularly for white paint. This oil yellows less, but it besides has some disadvantages : it dries more lento. Safflower petroleum is therefore not desirable for gluey use and lower key layers .
Glazing
Whether a painting is made using the wet-into-wet proficiency or painting in layers, a sugarcoat can be applied as a final layer. This is a crystalline paint level which has roughly the same effect as placing a colored sheet of glass over a picture. The video doesn ’ triiodothyronine switch, but the colours do. A sugarcoat can be applied, for model, if the artist is not quite glad about the colours and wants to change them reasonably without having to paint over stallion areas. besides, the artist may wish to achieve the ocular consequence of glazing layers ; an enamel-like top layer and deep color. An underpainting would then be used as a starting steer to modify the semblance of the entire paint with one or several layers of glass .
Brush strokes must not be visible in a glaze as you will continue to see the brush stroke of the underlie layers through the crystalline key ; a glaze medium therefore has to flow. Thanks to this property you can besides make flowing color transitions in a glaze.
A layer of glass has to be more elastic than the underlying key film as hera, besides, the ‘ fat over lean ’ rule has to be followed. diverse mediums are desirable for this function .
Storing and drying freshly-created paintings
The dry of the oil is a chemical procedure that occurs under the influence of breeze and light. oxygen is absorbed by the oil, causing the molecules to cross connect into a network. Energy is required for this oxidation process, which is supplied chiefly by ultraviolet easy. This stallion process takes some fourth dimension, which is the reason why petroleum paint takes so long to dry. The greater the ventilation and alight, the faster the dry. A humble ambient temperature and high humidity adversely affects the dry procedure .
This is whyfreshly-created paintings have to dry in a room with enough light ( not direct sun ), at around room temperature and low breeze humidity .
A paint has to be completely dry throughout before it is varnished !
3. APPLYING THE VARNISH
Varnishes for vegetable oil paints generally consist of resin dissolved in a solvent. They protect the key layer and determine the gloss of the work. A good varnish must be reversible. That is to say that, for exercise, in the case of a restoration it should always be possible to remove it with a solvent without damaging the paint layer, besides after many years .
Retouching varnish
During painting sunken-in areas can arise. This can occur if in a detail area excessively much petroleum is absorbed by an underlie layer ; the paint becomes flat and the coloring material loses saturation. Due to the impregnable suction of these areas, besides much petroleum would be sucked away when a adjacent level is applied. Once the sunken-in areas are hand-dry, apply a thin layer of retouching varnish in order to return gloss and color to the area, and consequently besides the harmony of the oeuvre. What ’ s more, this ensures that excessively much oil is besides not sucked away from a pursue layer. In a dilute layer after drying the varnish leaves a porous film into which a subsequent rouge film can adhere. When used for this lotion retouching varnish can sometimes besides be referred to as ‘ intercede varnish ’ .
In addition, retouching varnish can be used as a temp protective varnish on paintings that are not yet completely dry. This gives the painting an even gloss and protects it against crap. As the varnish is porous ( in a dilute layer ), oxygen assimilation and consequently besides the drying action of the paint can continue. Once the paint is wholly dry a final varnish can be applied over the retouching varnish .
It is very authoritative that the retouching varnish is always applied in very thin layers. If used as an intermediate varnish excessively much varnish will impair a dependable attachment of any subsequent layer. With excessive use as a temp protective varnish the solvent of the varnish can dissolve the petroleum from the lower key layers ( that are not however dry ) and bring it to the surface. If this happens the painting may remain awkward for many months or evening years, and will make it unmanageable to stop dust adhering to it. With normal layer thicknesses it is therefore authoritative to wait at least 2 to 3 months before applying it .
Final varnish
Oil paint dries under the influence of oxygen and inner light. This is a chemical serve. Once the paint is dry this oxidation process does not stop but continues in an age work. finally this can be visible as cracking. Once the paint is sufficiently dry ( with layers of normal thickness this takes approximately one year, with identical thin layers respective months less, and with slurred layers respective years ) it is consequently advisable to apply a final varnish. This concluding varnish slows down the oxygen concentration and consequently the age process. This besides determines the eventual degree of semblance and the rouge is protected against atmospheric contamination .
When varnishing ensure that everything ( painting, varnish, brush and trays ) are at room temperature. If a painting is taken out of a cold room into a warm room in order to be varnished condensing can form on the cold painting. Moisture would consequently be sealed within the varnish result in a white haze inside the film. What ‘s more, the moisture on the painting can cause the varnish to bead and decrease the adhesion .
Beading can besides occur if the rouge layer is very seal, for model when this contains a great deal of binder ( medium, petroleum ). In order to prevent this it is advisable to first wipe the paint with a fabric with some white spirit. Once the white spirit has evaporated the varnish can be applied.
glistening movie varnishes consist chiefly of a resin in a solution. In the case of flatness varnishes a mat agent has been added. When using a brush to apply a varnish with a felt agent ( therefore besides with mixtures of glistening and flatness varnish ), it is authoritative that the varnish is applied at the end in brush strokes in one commission. This helps to ensure a uniform degree of gloss .
What ‘s more, it is important that a varnish with a felt agent is applied in one layer. This helps to prevent differences in gloss and chevron formation. If, however, flat varnish is applied with a spray can, this can be done in several layers .
The matting agentive role in Talens Picture varnish flatness is a combination of waxes that flocculate under low temperatures. By heating up the varnish ( ‘ gold bain marie ’ or under trickling hot water ) the waxes are dissolved and the varnish can be used again .
