I have heard many variations on this and was wondering if there was any sort of agreement on the varnishing of acrylic paintings.
varnishing acrylic paintings can be a solution or a complete disaster ….it could be the nightmare for the unlucky conservator who will try to remove it in the future. let me state the obvious and common sense. if there is the need of varnishing an acrylic painting, one must use a varnish that does not contain solvents that dissolve the acrylic paint. the chosen varnish should also be removed in the future with solvents that do not dissolve the acrylic paint. it is true that varnish will protect acrylic paintings from dust and particles. acrylic paint can be dusted. but some dust may remain firmly attached to acrylic paint since the paint remains slightly tacky, especially in hot climates/seasons. so the layer of varnish may be a solution to this problem. now there is an ongoing debate on how to clean acrylic paintings from dust. some are in favour of using dry methods. others prefer aqueous solutions, stating that the water will remove the unnecessary additives inside the paint – such as emulsifying agent. for me, the simplest solution would be to avoid varnishing acrylic paintings. to reduce the problem of dust from adhering to the painting, i would advice putting a glass or acrylic sheet in front of the painting. this is definitely much more protective and reversible than varnish! of course its impossible to make everyone happy as some might argue that glazing is aesthetically disturbing. some might go as far as to argue that glazing might reduce the visibility of the paint’s texture or that a sheet of glass is a psychological barrier that separates the paintings from viewers – which might inhibit appreciation of the artwork. in any case i would insist in opting for acrylic sheet or glass. should glass be used, its important to make use of a laminated sheet, to limit damaging the painting in case the glass shatters. moreover, laminated glass offers a degree of ultraviolet filtering. and plain untreated glass is the best option. one should invest time in carefully positioning lighting to avoid intense light on the painting and reflections. moreover, thin spacers have to be used to keep the glass separated from the paint layer. we definitely do not want to have the paint sticking to the glass! …or flattening the paint layer! it is equally important to keep the reverse side of paintings distanced from the wall’s surface by at least 2 cm. of course direct sunlight would cook our paintings… so we need to avoid this at all cost too. finally, due to weight considerations, large format paintings might be more practical to be glazed with an acrylic sheet rather than glass. hope this helps!
varnishing acrylic paintings can be a solution or a complete disaster ….it could be the nightmare for the unlucky conservator who will try to remove it in the future. let me state the obvious and common sense. if there is the need of varnishing an acrylic painting, one must use a varnish that does not contain solvents that dissolve the acrylic paint. the chosen varnish should also be removed in the future with solvents that do not dissolve the acrylic paint. it is true that varnish will protect acrylic paintings from dust and particles. acrylic paint can be dusted. but some dust may remain firmly attached to acrylic paint since the paint remains slightly tacky, especially in hot climates/seasons. so the layer of varnish may be a solution to this problem. now there is an ongoing debate on how to clean acrylic paintings from dust. some are in favour of using dry methods. others prefer aqueous solutions, stating that the water will remove the unnecessary additives inside the paint – such as emulsifying agent. for me, the simplest solution would be to avoid varnishing acrylic paintings. to reduce the problem of dust from adhering to the painting, i would advice putting a glass or acrylic sheet in front of the painting. this is definitely much more protective and reversible than varnish! of course its impossible to make everyone happy as some might argue that glazing is aesthetically disturbing. some might go as far as to argue that glazing might reduce the visibility of the paint’s texture or that a sheet of glass is a psychological barrier that separates the paintings from viewers – which might inhibit appreciation of the artwork. in any case i would insist in opting for acrylic sheet or glass. should glass be used, its important to make use of a laminated sheet, to limit damaging the painting in case the glass shatters. moreover, laminated glass offers a degree of ultraviolet filtering. and plain untreated glass is the best option. one should invest time in carefully positioning lighting to avoid intense light on the painting and reflections. moreover, thin spacers have to be used to keep the glass separated from the paint layer. we definitely do not want to have the paint sticking to the glass! …or flattening the paint layer! it is equally important to keep the reverse side of paintings distanced from the wall’s surface by at least 2 cm. of course direct sunlight would cook our paintings… so we need to avoid this at all cost too. finally, due to weight considerations, large format paintings might be more practical to be glazed with an acrylic sheet rather than glass. hope this helps! David Frank Bugeja Paintings Conservator – Malta
I am so delighted that this forum is now launched. Congratulations to you all!! It is so valuable to avoid the chatter that exists within the internet to actually have colleagues discuss the issues from their perspectives, experience and research. The topic of varnishing acrylic paintings is in quite a flux among conservators. Within many conservation forums exists suggestions that one cannot successfully varnish an acrylic painting in such a way that it can be removed for treatment. As our experience and research suggests, quite the opposite is true. As Kristin recommends, it is first the artists choice whether to varnish or not. We always ask artists to consider varnishing as part of the painting process and not simply like putting plastic wrap over leftovers. We also suggest that varnishing needs to be practiced just like every other part of an artists practice in mark making. If aesthetically a varnish is required to pull together the various parts of the painting it is ultimately the artists’ choice. What we also suggest, (which is typically something a practicing conservator cannot suggest, and if the painting can support this) to add an isolation layer of clear non-removable acrylic to the surface of the painted, decorative surface. In this way when one then applies a removable varnish (removable in an alkaline water mixture) or a varnish removable with a solvent, as Kristin suggests with a low aromatic content, then the conservator treating the work is less likely to disturb the decorative surface of the painting. While it is true that glazing can be the best protection for an acrylic painting with the least amount of concern for removal, this is also true for every painting medium, whether in oil, watercolor, encaustics, etc……. I look forward to this lively and informative debate!! Mark Golden, Golden Artist Colors
Excellent question…there is a bit of an divided opinion on whether or not it is considered best practice to varnish acrylic paintings. Of course for artists another major concern often relates to how this may affect the final aesthetic of the painting. However, artists should note that acrylic films tend to be considerably more porous than oil/alkyd films and can therefore suffer from the accumulation of dirt and grime over time. If a varnish is applied, artists should choose a non-yellowing, reversible varnish layer to prevent dust and and other airborne particulates from becoming embedded into the upper paint layers. In the long term, artists should also realize that acrylic films can possess additives that may migrate to the surface over time. This can create a hazy and/or cloudy appearance that may or may not require the eventual removable of the varnish layer. If a varnish has not been applied it may be possible to carefully brush away some of these additives; however; in some cases these materials reappear on the surface as they can continue to remain mobile depending on a variety of factors. To address this problem (note all acrylic paintings suffer from this), some manufacturers advise applying a thin layer of clear acrylic medium over the surface to serve as a barrier between the varnish coating and the paint. As high quality acrylic mediums do not yellow/discolor significantly with age (as do oil and/or alkyd mediums), this layer can potentially serve as a protective barrier should the varnish need to be removed.
David Frank Bugejia – Thanks so much for your suggestions….one thing that I would add is that odorless or low-aromatic mineral spirits is the one solvent(s) that has been shown to be safe to use on acrylic paintings. Many proprietary varnishes available today are already dissolved in such solvents so dissolving your acrylic paint while varnishing is not of huge concern….however artists should avoid using high proportions of aromatics in this instance….if not for safety purposes alone! More information on solvents can be found in the “Solvents and Diluents” pdf located in the Resources section. Glazing/glass is of course always an option for easel paintings (again check the “Storage, Exhibition, and Handling Tips” pdf in Resources to learn about the wide range of glazing options available today). While certain things may be “nightmares” for conservators, artists are always free to choose what materials they use and the techniques they employ. Whether or not you decide to varnish your painting, please record whether you do so and what you use on the back of the artwork so that conservators in the future will know how best to care for your painting… Deghetaldi, Kristin