Things that Can Go Wrong in Oil Painting
While oil painting is a generally forgiving medium, there are still things that can go wrong and mess up your
painting if you were not aware of them.
Fortunately, you can easily avoid the most common mistakes if you work by certain guidelines. Better yet, some
mistakes can be corrected.
When assessing the quality of a completed oil painting, the hardest part is that it takes some time before it
properly dries, after which the damage can become manifest.
In other words, after enough time has been allowed for the painting to dry and at times even longer, cracking or
drying out of the color mat happen. However, in majority of cases, the cause is easy to identify.
This is one of the most destructive effects of poor oil painting that happens very frequently, resulting from
the sinking of the top layer. This is in turn caused by the rapid evaporation of the oil in the color, causing the
layer to sink into the one below.
If your painting has spots of dullness after it has completely dried out, or its overall appearance is dull,
then it needs ‘oiling out’. Besides making your painting susceptible to cracking, it also makes the painting’s
finish uneven and blotchy.
This dull finish is mainly as a result of a wrong ratio of drying oils to solvents and paint. Precisely, it will
occur when the concentration of the solvent is too high in the paint. For the early layers, this may be fine but
for the top layer, it leads to a dull effect. An overly-absorbing surface is another common cause. Ensure that the
painting surface you use is well primed so that the paint does not easily sink into a porous surface.
The good news is that you can use ‘oiling out’ to regain your surface’s sheen. In this process, an all-purpose
medium, such as linseed oil mixed with 50 percent mineral spirit, is rubbed into the dull spots.
Use a soft piece of cloth to gently rub in the oil mixture, cleaning away any excess. When you apply varnish on
its own minus the oil, you’ll solve the issue. You may apply it after oiling out and letting the painting dry thoroughly.
When a top layer of paint is much drier than the one beneath it, it will usually result into a cracking effect
on the painting. If the top layer dries faster and the bottom layer dries at a much slower pace, the top layer will
crack due to the brittleness that results.
This kind of problem in an oil painting cannot really be repaired. If you apply another medium or more paint,
you only make it worse. Therefore, it is better to prevent cracking from the beginning.
The simplest way to ensure your painting dries at a
uniform pace is to use the right mediums and layer in the correct order. Oil painters use a traditional rule
known as ‘Fat over Lean’. Put differently, you should increase the proportion of medium used in each layer when
you’re painting in layers. Here’s an example:
First Layer – Very Dry; less color more solvents.
Second Layer – Dry; more solvents, more color.
Third Layer – Medium; less solvents, a bit of drying oil and some color.
Fourth Layer – Oily; color, drying oil, little or no solvents.
When you use too many different types of medium, you put the painting under ‘stress’. In this case, it’s not
easy to predict the damage. You can easily mitigate against this problem by using the ‘Fat over Lean’ method. Use the same type of drying oil and solvent
in each layer. If the mediums you’re using are ready-made, don’t mix them with others; only do so with solvents if
you have to.