Varnishing Tips for Oil Paintings – Retouch vs Permanent Varnish

Many artists are mystified by the varnishing process, and there is much debate over the subject.

But most agree, varnish should be used to protect paintings from pollution in the atmosphere, UV rays and scratches. Another factor is as oil paintings dry, the dark colors have a tendency to ‘sink’. Varnish brings out the rich colors and the brilliance they had when you first applied them.
Here’s the problem, it can take 6 months to a year or longer for an oil painting to completely dry. So, what does the artist do for those dry-to-the-touch paintings that are commissioned art, done in a hurry, or ready for a gallery opening and in need of some ‘varnish’?

I use the temporary varnish, otherwise known as Retouch Varnish, because it dries quicker and is a great medium to use for those ‘uncured paintings’ that need a finished look before they are completely dry.

Temporary/Retouch Varnish – why & how:

• Retouch varnish can be applied to paint which is “hand-dry”.
• The thin retouch varnish layer allows the paint to continue its deep drying thus avoiding cracking.
• Temporary varnish can be easily taken off of a painting before the final permanent varnish.
• I have always temporary because I usually sell my paintings before they sit around in my studio for 6 months!
• Retouch varnish is also excellent at reviving dull spots when you come back to a dry painting and want to blend dry and new wet oil colors together.
• Ideally, you want a clean, dry room with a large surface to lay your painting down to varnish it.
• Spraying can make it easy for an even coverage.
• Retouch Varnish is effective as a spray because there is less of a chance of smearing any semi-dry paint. If a color is not completely dry the turpentine in the retouch varnish can loosen the paint if applied with a brush.
• That said, I don’t like spray fumes and prefer to ‘brush’ the varnish on using a foam-sponge brush for easy clean-up.
• Brushing makes a thicker coat but may take more time to dry.
• Retouching varnish doesn’t have the quality that a finishing varnish has. A finishing varnish makes your painting look better.
• If the painting sells before the finished painting has cured for 6 months (4 – 5 months if thinly painted), use a temporary/retouch varnish.
• The new owner/collector of the painting can take it to a art curator for a final varnish after the painting has cured.

Permanent varnish:

• This is a much more complicated subject.
• The final varnish is best applied with a brush because it provides more even protection for the painting.
• There are many varnishes from high-gloss to dull, from yellowish to clear, ones that have longer lifespans, others that can be easily removed and others that can’t.
• You can buy pre-made varnishes or make them yourself.
• Two coats should be used for the final varnish.
• Allow each layer of varnish to dry overnight.
• Apply the varnish with a soft brush on a horizontal painting.
• Use even strokes in a single direction for each layer.
• The new owner/collector of the painting can take it to an art curator for a final varnish after the painting has cured.
• Check out, “The Artist’s Book of Materials and Techniques” by Ralph Mayer with 28 pages full of varnish facts.

Tips for both Temporary/Retouch or Permanent Varnish:

• Use a lint-free rag to gently wipe all dust and hairs from your dry-to-the-touch painting.
• Work in a dust-free area.
• Keep your pet friends out of the area during varnishing time!
• Varnish your painting in one sitting – If not, the painting will have a line where the wet varnish meets the dry varnish.
• Make even parallel strokes using equal amounts of varnish on all parts of the painting.
• The varnish should be dry in a day or two.
• As the varnish dries, a chemical process takes place in which the resin releases a vapor which is harmful to your health, so provide good ventilation to your workplace!
• A thinly applied varnish will look better and more professional.

*Please comment if you have any other thoughts or suggestions that can help others. Permanent varnishing tips would be extra helpful! Thanks to my Twitter friend and fellow artist Nadine Robbins for sharing some of her varnishing suggestions that were included in this article. ~Lori