I pour the varnish out of the bottle into a small container that’s wide enough for the varnishing brush I’m using. I definitely recommend buying a quality varnishing brush, as it makes applying the varnish smoothly much easier. I always pour out more than I think I might need so I don’t have to stop varnishing until I’ve finished. I usually dilute the varnish slightly with water, following the instructions on the bottle; this makes it spread more easily. Any leftovers I pour back into an old varnish bottle that’s marked “working varnish” so I can distinguish it from undiluted varnish.
Varnish on acrylic painting
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- Forum Member +
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Posted 7 Years Ago
I did a stupid thing two days ago. I decided that my acrylic painting on canvas looked positively dull and so I sprayed it with a varnish that was OK to use with Oils or Acrylics. I was rather heavy handed with the spray and when the varnish became touch dry ,to my horror, I found that in certain areas the paint had lifted off the canvas. Do you think that it would be alright to repaint those areas over the varnish and then respray or should I remove the varnish which may also lift even more paint or shall I file the painting in the bin? Please don’t ask the make of the spray as I have used it for many years over oils without any problems . It’s just me being heavy handed. It’s the first Acrylic painting that I ever varnished. Why did I do it.
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Posted 7 Years Ago
Oh Lord . this is really, really difficult. If you paint over the varnish, then re-varnish, you might be lucky. But if you ever sell the painting, do stick a note on the back to explain what you’ve done, because anyone removing the varnish in subsequent years is going to take a chunk of painting with it. If you try removing the varnish you’ve applied, I suspect you will indeed remove even more paint with it: it depends on why it lifted in the first place (see below!). It also depends partly on how thick the paint is – is it just wearing away, or lifting as if there were a bubble beneath the paint? If the former, try gently removing the varnish in the affected area, repaint, and re-varnish. If the latter, the problem is insoluble – the board is at fault: could be oil-primed, or greasy. This is one reason why the art tutor Will Kemp advises adding an isolation coat of medium to acrylic paintings before varnishing them. I strongly suggest that you go to his site (just Google Will Kemp) and find your way to his forum/blog pages where he deals at length with the issues of varnishing acrylics. But there’s a big question in my mind here: even if you overdid the varnish – and that’s not hard to do with a spray-on type – you might have got a nasty mess on the surface, but it shouldn’t have lifted the paint, unless one or both of two things occurred. One, the paint was too recently applied, so hadn’t proved: I would always give an acrylic painting a week or so before varnishing it (I’m also assuming these weren’t interactive acrylics – if they were, you’ve just reactivated them by making them wet). Or two, there was an anti-fungicidal substance added to the gesso priming, which failed to provide enough adhesion for the paint; and the moment you added varnish, it lifted. This happened to me – and by the way, when it did I actually did remove the varnish, very carefully indeed, repaint, and then re-varnish. Even some well-made canvas boards – and for all I know canvases – are at risk of this happening, although so far I’ve only found the problem with stores’ own canvases: ie, canvases from Winsor and Newton, Daler Rowney, and Loxley do not suffer this problem. Go through your stock of canvases/boards – hold each one up to a raking light; if you see any shiny element in the weave, as if it might be cellulose . not a sheen, but something that glitters. wash the canvas with cold water and a nail brush; even use a little household soap if necessary to get the stuff off. Then dry it, ensuring no soap remains, and apply a coat of acrylic gesso: the one I use is Daler Rowney’s Cryla gesso. Also – although I’m afraid some will deny there’s a problem – write to the supplier and maker of the boards, should they be different, and tell them what happened to your painting. Canvases and boards should not be sold in this condition, they’re an invitation to trouble.
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Posted 7 Years Ago
I would be worried about spraying varnish on anything as its not very environmentally friendly. When I varnish acrylics, I paint it on and have not had any problems with it. I’ve even been able to paint over it in acrylic or oil. Sorry I can’t help with your current problem though.
- New Member
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Posted 7 Years Ago
I know this reply might seem ‘past the post’ as you’ve, thankfully, resolved your problem but I’d just like to add a word of caution about spray varnishing too. I’d finished an acrylic painting on linen 80 x 100cms which I was really pleased with but, like you, wanted to bring the colours up a notch with a coat of varnish. (The painting had dried for well over a week.) I’d never had a problem in the past with smaller pieces but on this occasion the varnish went very patchy. Panicking I put another coat on when the first was dry but that just made matters 1,000 times worse (it was a black background so I suppose it showed up more). In the end I took the varnish off as best I could with white spirit (an awful lot of it!) and thought that I’d got it all off. I washed the surface and was amazed that the paint and support had actually survived the bad treatment I’d given it. However, on retouching areas I found that I hadn’t eliminated all the varnish and small areas of varnish remained – obviously not as thick as in the first place. The background still looked blotchy. In the end, after much hair pulling and head scratching, I put a coat of acrylic matt medium over the whole thing. Things started to improve so I put another coat on. I don’t think you’re supposed to use matt medium without mixing it with acrylic paint but when needs must . Anyway, the canvas then looked 100% better than it had done after the spray varnishing incident. I’ll never use spray varnish again on larger pieces – it’s just not worth the risk – and I don’t think it’s got anything to do with being heavy-handed as I did have a brush ready to immediately rectify any areas which looked over-varnished. I’ve no idea how the painting will fare but am keeping my fingers’ crossed it’ll be OK.
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Posted 7 Years Ago
Just a quick addition in view of Maureen’s reply – varnish always needs to be applied very thinly. You can always add further coats when one has dried, but many problems are caused by a too-thick varnish (or one that’s been shaken, unless you’re after a bubbly effect). I suppose a very fine spray could achieve that, but spray nozzles get clogged, and then horrible globules of the stuff can suddenly land on your painting. It may be a bit of a fag, but I believe the best approach, whatever varnish you’re using on whatever surface, is to pour it into a container, leave it to settle in a warm room, and then to apply it in thin layers to the painting. A problem I get now and then is streaking, which suggests the varnish was too cold and gelid. I don’t actually use the Will Kemp method – involving the application of an isolation coat of medium, available from Golden Acrylics, but it might solve a few problems if we did.
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Posted 7 Years Ago
Yes, first coat one way, let it dry, the second coat another: the 90 degrees idea is probably a good one, and it’s probably getting careless about it that has caused the streaking on some of mine, plus using the varnish a bit cold. Yours smells? Hmmm. a water-based varnish, I assume, in which the water has become rancid: that can also happen to some of the more fluid acrylic paints – I opened a pot of ultramarine the other day, and it smelled as if something had died in it. The paint was OK – but yes, I think I’d ditch the varnish. Oh, and the layers – it depends on whether I want a high gloss or not – usually, the most I’ll give a painting is two, and often just one will do.
- Esteemed User
- Last active: 3 years ago
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Posted 7 Years Ago
I have varnished my acrylic paintings on canvas, canvas panel, wood, and even fine art paper and never had any problems. I must have been very lucky to have escaped the difficulties you have encountered. Mind you I do not use sprays.
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Posted 7 Years Ago
And you probably use higher quality boards and canvases than some – never worth economizing on supports, since that’s where at least some of the trouble lies.
Types of Varnish
You’ve a choice between gloss and matte varnish, applied either with a brush or out of a spray can. Gloss varnishes dry completely clear, but a matte (sometimes called satin) varnish leaves a slight frosted-glass appearance, so you might lose finer detail in a painting if you use it.
A varnish should ideally be one that’s removable (check the bottle label, it will tell you) so that it can, at some future date if it has discolored, be removed easily and replaced. Varnishes for acrylic paint are either water- or solvent-based.
Using a medium that you’ve used in a painting as a final varnish is not recommended, because if this layer is removed at some future date when a painting is cleaned, the painting itself may become damaged.
When to Varnish
It’s crucial that a painting is completely dry before it’s varnished or the varnish may crack. Waiting for a painting to dry thoroughly is less of an issue with acrylics than it is with oils (some experts say you should allow at least six months). If you want to even out the gloss on a not-yet-dry oil painting, use retouch varnish.
Varnishing is not something to be done in a rush; why risk messing up a painting in this final step? Make sure the painting is free of dust; that the varnish flows evenly without leaving brushmarks (dilute it if necessary), and use a suitable varnishing brush.
Altering a Painting After Varnishing
If you’ve used a removable varnish, hopefully you’ve still got the bottle so you can follow the instructions to get it off. Otherwise, paint on top of the varnish and then revarnish the whole thing again (and hope that you’re not still around if someone tries to remove that layer of varnish and ends up taking off the extra paint and the varnish beneath it too!).
If you’re using a matte varnish, Mark Golden of Golden Paints recommends you put a “gloss coat down to first seal the surface, then to apply a matte or satin varnish” as this “dramatically improves the clarity of the final finish whether it be gloss or matte or anything in between”. Giving this tip in his blog, Golden admits that artists may find it “counterintuitive”, but also says “Folks really, really need to practice varnishing! It is the one critical thing missing from most artists toolbox of skills.”
