Advice: Varnish or not to Varnish Your Artwork?

Artists ask me this question more often than any other when talking about techniques in artwork. What is varnish, what does it do and why do we use it?

Varnishes can assist your art work in several ways. You can use them to change the surface gloss, making it more matte or more glossy, or you may need to give the various areas of a painting a more unified finish. They can also be used to increase the colour saturation. Varnishes also offer protection for the underlying surface and make it easier to clean the art work. Some varnishes offer additional protection in the form of Ultra Violet Light Stabilisers, which help stop UV radiation before it comes into contact with the artwork as this is where damage can often occur.

Varnish is used as a final layer and is applied to a painting after it is finished and completely dry. It’s used on paintings that are not going to be framed under glass and is there to protect them from environmental pollutants like dust, dirt and other airborne pollutants. Varnish should be used to even out the final appearance of a painting, making it all equally glossy or matte as often art work has uneven patches of glossiness that can be distracting to the viewer if not corrected..

It’s important to know what type of varnish you should use. You have a choice of gloss, satin and matte varnish, of which each can be applied either with a brush or from a spray can. Gloss varnishes dry completely clear, but the satin and the matte varnish often leaves a slight frosted finish, so you might loose finer detail in a painting if you use them.

A varnish should ideally be one that’s removable it should tell you on the label. The reason for this is so that it can at some future time be removed easily and replaced if it has become discoloured or cracked.

It’s really important to make sure your art work is completely dry before applying varnish or you could have issues with the varnish cracking or crazing. Obviously it’s less of an issue if you paint with acrylics. Oils are another story all together. It is best to wait at least 6 months and even up to a year if you use a thick impasto technique.

When it comes to actually applying the varnish, these tips may be of help for you

• Make sure that the art work is free from things like dust and hair etc;
• Try to varnish in a cooler part of the day as you don’t want it drying too quickly especially while mid process.
• The varnish needs to flow evenly without leaving any brush marks so dilute it if it’s too thick.
• Use a suitable flat bristle brush that is just for varnishing purposes.
• Make sure you work in good lighting, preferably from a window; it helps to see any missed areas and also any particles like hairs that may have slipped off the brush etc.
• Work from top to bottom or vice versa, try to not do patchy areas or go back over already done areas as it can dry quickly and lift off or go cloudy.
• Use a container that is wide enough for the brush rather than trying to use it from the bottle you can dilute it easier that way too, without affecting the whole bottle.
• Apply two or three thin coats of varnish rather than one thick one. And try to let each coat dry fully in between, usually over night is best.
• Do each coat a differently, vertical strokes then the next coat horizontal for instance.
• Leave the art work flat at first to dry to prevent any runs and don’t forget to let it dry in an area free from dust, animals and movement that can stir up dust etc as the sticky surface will attract and hold onto such particles, ruining the finish.

All in all don’t be afraid to work with varnish, if you use a good removable one you can always start over again