Imagine finding out that the masterpiece you were working on all week has dried to an uneven dull luster. What do you do? Shout or cry for starters, maybe? Then you find out that there is an easy fix to this common oil painter’s problem and it’s called oiling out.
Patches of dull or sunken sections of paintings indicate sinking of the paint film which can be caused either from using too much or little medium or having an over absorbent surface. The most appropriate and easiest way to lesson dull patches in your work is to paint on an oil primed surface. Historically this type of paint surface has proven to stand the test of time as a prevention for ‘sinking’ patches.
What causes the sinking of paint film?
Paintings that are worked on over a period of time may have pigments that dry at different rates. The various degrees to which the pigment absorbs the linseed binder will directly affect the drying rate and the final sheen. Also overusing medium will dilute the color and will impact the drying rate as well (Remember to never use more than 10% medium to paint ratio). Much like the support surface, using a good quality medium in your work will lessen the sinking effect.
Generally speaking, the problem of sunken oil paintings is a problem for those artists who build up oil colors in layers as opposed to those that paint all prima, without mediums. What tends to happen is that as the further layers are added, the absorbent under layer sucks the oil from the fresh layers, leaving them looking dry and lifeless.
What is oiling out?
It is a process where a solution is applied to a dry painting restoring it’s luster. Traditionally, an old masters method was to mix stand oil or sun thickened linseed oil with mineral spirits or turpentine, ratio 80/20 and then apply this mixture evenly across the whole surface. This method, although effective requires waiting days before further layers can be applied. Alternative method, if time is short is to brush little retouch varnish or some pre made artist painting medium. It dries quickly, however because it may be a soluble resin, subsequent oil colors may be susceptible to cracking.
I have tried a number of different formulas over the years, but the one I find most flexible and effective is equal part Gamblin gamsol and Gamblin galkyd medium. It is a fast drying solution that will leave you with a glossy finish. If a more matte finish is required you can always add cold wax medium to the mix.
What is the procedure for oiling out?
The materials required are a good old bristle brush. I use a filbert as circular motion is recommended to get into all of the crevasses. You may also need a lint free cloth to wipe off excess solution. Remember that a little goes a long way with this process. And of course you need your pre-mixed solution. Note: That you can use some gloves as you may come into contact with the solvent.
As you can see in this close up photo, some areas of my painting ‘Yonge Dundas square’ have dried glossy while other matte.
As you can see in this after image, the surface has been unified. Make sure when applying to not miss a section. You can use side lighting to verify whether the whole painting is covered. When dry the work will look glossy and fresh.
Oiling out is a wonderful and easy way to restore life back into an old, dull looking painting. Make sure that the surface is clean and touch dry when applying. If you can still see dull areas after the first coat, apply another until the whole surface is unified. Lastly, remember that varnishing a painting will not have the same result as oiling out does. A varnish will make a dull areas shiny while making the shiny areas shinier, thus leaving an inconsistent looking surface. Happy painting.