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How should varnish be applied? There are probably several ways, including simply spraying it on. The traditional way that virtually guarantees a good result is to do it with a brush. I have several hog bristle brushes for oil and several synthetics for acrylic that I reserve for varnishing, so that there is never any pigment residue in the varnish brush. I apply acrylic varnish the same way that I apply Damar varnish to an oil. If the painting is an oil, first check the surface to see whether some parts look very dry or matte. Just varnishing may not resolve this issue, since the varnish can just sink into the matte portions of the painting. The solution is to brush linseed oil or a medium like Liquin into the matte places and rub the excess off with a cloth. When the application has dried, then apply the final re-dissolvable varnish. Typically, the final varnish should only be applied after the painting has dried for several months. If the paint has been applied thickly, six months. (The reason for waiting is that oil paints dry by oxidization and a final varnish that prevents contact between the paint and the air will interfere with the drying process.) If the painting is an acrylic, some painters will apply two different varnish coats, first a clear acrylic coat that provides an isolation layer over the paint. Given the rapid drying time of acrylics, varnish can be applied after several hours in the case of thinly applied paint or after an interval ranging from several days to a few weeks in the case of more thickly applied paint. This layer will not re-dissolve. After it dries thoroughly, a coat of re-dissolvable or removable varnish can be applied. When applying varnish, I begin in the upper left and varnish a square portion about 6-8 inches, brushing first horizontally and then vertically. Then I work across the top, in a series 6-8 inch squares, blending the edge of each new square into the previous, repeating the process all the way across the canvas. When I get to the far right, I move down to the next unvarnished section on the left and work across, again in 6-8 inch squares, etc., until the whole canvas is covered. I try to apply the varnish evenly and thinly. It is also better to apply two thin coats of varnish than one thick one. While the varnish is still wet, I look at the entire canvas at an angle to see if I have missed any spots. Usually the technique of brushing first horizontally and then vertically covers very well. On a really big painting I might increase the size of the squares. On a really small painting, I do the whole thing at once. When finished applying the varnish, lay the canvas flat, so that the varnish does not run or drip, in a dust free area. Do you varnish? And how do you do it?

Quite a few painters today don’t apply a coat of varnish to their work on completion. I have even spoken with a few painters who didn’t know that varnishing has been the traditional last step of the work of oil painting. Others wonder whether varnishing is useful. And then there is acrylic paint which behaves and displays differently from oil. So then, why varnish? I can think of several reasons to varnish a painting. For one thing, this is the way that traditional paintings were finalized. If a more or less traditional appearance is desired, then varnish. Varnishing is also a way of getting rid of the contrasts between dull and glossy portions of a canvas and achieving a fairly uniform surface. Given the range of art varnish finishes, varnishing doesn’t necessarily mean the creation of a glossy surface on the painting. Matte varnishes are available. It is also true that a good varnish, particularly on an oil painting, will make the colors appear richer and more lively and even add to the sense of depth in a painting. And then there is the issue of preservation. The traditional practice achieved the visual results just noted, but more importantly, it was intended to protect the surface of the painting. Dust and dirt can collect on the surface of a painting and even get embedded in the surface. A final varnish like Damar is re-dissolvable and can be removed with mineral spirits or turpentine without disturbing the oil paint layers below it, where the linseed oil that binds the pigment is no longer soluble. Remover the varnish and remove the dirt. Once cleaned, the painting can be re-varnished. All of this applies to acrylic painting as well. Acrylics themselves, like oils, do not re-dissolve, and this includes clear acrylic mediums used as varnishes, but there are final re-dissolving varnishes that can be used on acrylic paintings if desired. Let me know what you think about varnishing.

Most painters have favorite brushes and distinct brush preferences. Some of these preferences may be purely sentimental. I have a Grumbacher “Gainsborough” size 16 China bristle that I bought over forty year ago. I treat it well and enjoy using it. I am also not very fond of synthetic bristle, probably just because it is synthetic and unnatural. But there is another, quite objective, reason behind brush preferences. There is a very real relationship between paints and the brushes used to apply them. Natural hair and natural bristle brushes behave very differently from synthetic fibre brushes. Oil paints and acrylic paints also behave very differently. Nobody who has tried out different brushes and different paints would argue about this. It is probably also the case that natural fibre brushes work best with oils and synthetic fibre brushes work best with acrylics. Paint made with natural media—oil and resin—wants (or at least deserves) natural brushes. And paint made with synthetic media begs for synthetic brushes. Synthetic brushes have a somewhat different feel from natural brushes—they lack the snap of a hog bristle brush and the soft synthetics flex differently from sable and ox hair. My personal preference is for the natural bristle or hair brushes when painting in oil. Natural bristle responds beautifully to oil and resin. And properly cleaned after use, a natural bristle brush can last for decades, like my favorite Grumbacher, The issue with acrylics is very different. Given the use of water as a thinner and a cleaner in acrylic painting, a good natural bristle brush will have its characteristic snap at the beginning of a painting session but will gradually become more and more soft, even mushy, as painting progresses and water affects the bristles. A synthetic bristle will be impervious to the water and will retain its feel throughout the session. It is a good idea not to use the same brushes for oils and acrylics, given that cleaning procedures are different for oils and acrylics and that there is often some paint residue left in the bristles up close to the ferrule even if they are well cleaned. If you paint in both oil and acrylic, have two distinct sets of brushes, regardless of whether you choose to paint with only one kind of brush, natural or synthetic. I keep a full set of natural brushes with my oils and a full set of synthetic brushes with my acrylics. Any thoughts from others? What are your brush preferences?