Tips for Varnishing Paintings
Varnishing your paintings has a number of benefits. It is a way to add a layer to your paintings to protect them from the dirt, dust and even pollution in the air. Varnish comes in many different types from glossy to matt and so you can achieve a finished look to your painting. It provides an alternative to putting the painting behind glass and often enhances the colours in your artwork.
A Key Question
So before you go ahead and start varnishing your painting - what type of medium or paint have you used to create your artwork?
How you varnish your artwork will depending on what type of paint or medium you have used to create it. Here we look at a range of different mediums and offer up some tips for varnishing them.
Oil paintings will take time to dry completely, so if you are wishing to varnish your work then consider how long the oil paint has been drying.
If the answer is less than 6 months, it is best to use Roberson Exhibition temporary varnish or a Re-touching varnish (re-touching varnish has the added advantage of equalising the surface areas if, as occasionally happens, the paint appearance is matt in some areas and satin or glossy in others.)
Oil paint dries from the outside in, although the surface can feel dry the interior will take months to completely dry.
After 6 - 8 months think about what type of finish would you like to achieve? All oil paint varnishes are solvent based but you have the choice of gloss, satin or matt finishes. Matt and satin varnishes generally have an element of wax added to the recipe to achieve the final finish. Matt varnish can tend to separate and it is useful to sit the bottle in warm to hot water to allow the wax to dissolve properly before painting onto your work.
Spray varnishes work well and with practice you can achieve an even dispersal. It is more common and more economical to use liquid solvent varnishes and the brush you use to apply your varnish is important. Choose a smooth, soft flat brush (the width you need will depend on the size of your painting). Some artists use priming brushes but I find these too absorbent and thick, the varnish tends to be applied unevenly. Da Vinci 5040 Mottler varnish brushes are beautiful but pricey, look after them well!
Some varnishes have added UV protection. It is a peculiarity of oil paintings that if placed on the wall in a sunny spot the colour deteriorates from the interior base layer first so you won’t see the fading until all the oil paint colour is gone and it’s too late.
Shellac Varnish – A useful varnish for painters and printmakers. This is a fast drying varnish which is popular as an isolating varnish, often used as a sealer for absorbent surfaces and recommended for metal leaf to prevent tarnishing.
Dammar Varnish – recommended as a final picture varnish once your oil paintings have dried out completely. You will achieve a subtle gloss finish with the added advantage of providing a protective layer.
Golden MSA Varnishes - A non yellowing spirit based UV varnish tested and manufactured my Golden to have quality UV filter. This MSA UV Varnish is a solvent based clear varnish, tough and long-lasting. Available in Gloss, Satin & Matte.
How hard-wearing do you need the varnish to be?
As well as having the choice of all solvent varnishes you have the option of using a water-based acrylic polymer varnish. These varnishes will keep your canvas clean and are perfect for interior paintings if you need an exterior varnish and wish to stick to an acrylic base Spectrum have a great Exterior Acrylic option.
Polymer varnishes are available in different finishes the same as solvent varnishes so you can choose between gloss, satin and matte.
Acrylic paint is fast drying but best practice is to leave your art work for at least two weeks before varnishing.
As these works of art are generally on paper and quite often protected inside a glass frame a varnish is not required. However for the purposes of protection against fingerprints, humidity and dust Schmincke has a very useful aerospray which when applied in thin layers will not change any colours in your work. Their Universal Fixative spray is another useful product which will protect charcoal, pencil, pastel, watercolour, gouache, art prints, ink-jet prints and photographs with a fast-drying, age-resistant, colourless, alcohol-based spray.
Works on paper are best treated as watercolour paintings, use a fixative if required for added protection.
Depending upon your mix of media you can use acrylic, solvent and fixatives. Stick to the rules and just use a solvent varnish if you have used any oil based products such as oil paint, oil pastels or oil bars.