Have you ever asked how to properly store oil paintings once completed? Maybe you asked yourself even how to avoid yellowing in oil paintings.I guess yes also because oil paintings are not like other kind of artworks; they have features that you need to know in order to avoid bad surprises once your work is complete! If you are wondering how to correctly store oil paintings you have found just the right place, what stroke of luck you had!
Many people think that oil paintings,once completed and dried, remain unchanged over time…well that’s not exactly true! The colour chemistry is not an opinion,like math, and follows precise rules that you need to know in order to avoid unpleasant surprises! Everyone who paints with oil colurs knows well that sometime in order to complete a work, it takes months, even years in some cases; it depends on the difficulty and on the size of the canvas.
Once dried oil colours tend to darken rather than to fade; indeed you will never see a oil painting faded or discolored or without chromatic strength, precisely because oil molecules provide intensity, brightness and resistence over time. The issue of conservation of oil paintings lies in the fact that layers of colours dry in different ways and times. It can cause some problems to the beginners. The main problems do not come from dark colours,but rather from light ones, and i refer in a special way to white.
HOW TO AVOID YELLOWING OF WHITES
The most common problem that arises when you leave to dry a completed oil painting is, without any doubt, the yellowing of light colours and mostly of whites ones. It often happens that sometime after months in which you leave of drying your painting,light colours or perhaps pure white used like final light points, get yellow turning towards a pale yellow or even worse a lemon yellow. Why does this happens? Each painter knows well how slow drying of oil colours is, which need from a minimum of six months to a maximum of a one year to dry perfectly! It takes ages and you should consider also the fact that if you have painted the artwork with layers of colours thick and textured,called also “impasto”, painting may need even two years to dry completely!
Some restorers claim even that oil paintings never dry completely,actually their drying process continues over time constantly. It should make clear as oil paint is unique and particular and it needs deep and technical knowlegde. Many beginners think oil colours is dry whey they touch it with their own hands and it no longer sticks(dry to the touch)but they are very wrong! All of this leads us to understand that white colour,during drying process,is quite sensitive and if you really want to keep it white over the time you will have to implement some simple but essential measures.
The first important tip that you must put into practice is to dry oil paintings to LIGHT. You NEVER to dry oil paintings in the dark or in low light, since lack of light inevitably will yellow whites,but not only!
I’ll give you one more example: you painted a cobalt blue sky that perhaps represent a spring day. You wish that blue reamains the same over the time. If you, however, will dry oil painting in the dark you will notice that blue intense and brilliant has turned into a blue that tends to green due to yellowing caused by a lack of light! Drying in the dark must be avoid at all cost, whether after moths of hard work you do not want to find different tints from those that you used. That’s not the only case that will yellow a oil painting and now let’s see why!
WHAT KIND OF OIL SHOULD BE USED
When you paint with oil colours you can use various kind of oils. What oils should be used to get better results? Usually linen oil is the most used,but can you use it in any case? The answer is NO! There are many other kind of oils to be used like walnut oil,poppy oil and safflower oil! It is essential to use the right oil in order to avoid the yellowing of colours mostly of whites and now we’ll see why. Each of these oils yellow in different ways and degrees that you must know to use them in the right ways. Linen oil tends to yellowing more compared to other oils so you should avoid it when you use whites. You also should prevent its use for final retouches because even if you leave your painting to dry to light,the colours will yellow anyway. Let’s see the different yellowing degree of various oils:
-LINEN OIL-YELLOWING DEGREE = HIGH
-WALNUT OIL- YELLOWING DEGREE= MEDIUM
-POPPY OIL- YELLOWING DEGREE= LOW,ALMOST ABSENT
-SAFFLOWER OIL- YELLOWING DEGREE= LOW,ALMOST ABSENT
As you can see poppy oil and safflower one have a low yellowing degree compared to other oils. So you should use them with whites,for final retouches and overall for the last layers of painting. In general you can use linen oil or walnut one with dark colours and earths as well. The only weakness of poppy oil is its very slow drying as well as safflower oil which is even more slow. In order to help solve this problem you can use a desiccant,but don’t overdo it!
Another important element to consider,would be to choose a brand of colours with good pigmentation! Colours with medium- high pigmentation will provide a great resistence both to yellowing and light! This measure could avoid bad surprises after long period of drying. Therefore to conclude, let’s sum up what measures to take to avoid the annoying yellowing of oil paintings during drying process:
-LEAVE TO DRY PAINTINGS TO LIGHT AND NEVER IN THE DARK
-USE OIL WITH LOW YELLOWING DEGREE AS POPPY OIL OR SAFFLOWER OIL
-BUY COLOURS WITH MEDIUM-HIGH PIGMENTATION
You will see that by following these simple but essential rules,you will avoid such irritating problem to have paintings with different tints compared to those you wished, due to yellowing that luckly can be avoid.
Hoping that this article can be useful to readers i conclude as always, wishing you good paint!