Home Forums Explore Media Casein, Gouache, and Egg Tempera Casein as an underpainting for Acrylics

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  • #472256

    I have used acrylics as a value underpainting for caseins in the past.

    https://www.wetcanvas.com/forums/showthread.php?t=1436341

    I was wondering if I could reverse that process and paint acrylics over a casein value study. I wanted to try this as acrylics can be transparent. You can see the result below. It was not terrible result but getting a smooth stroke was difficult. It might be worth a further try. C&C welcome. Gary

    6×8 casein as an underpainting value sketch on Raymar Panel
    [ATTACH]865368[/ATTACH]

    6×8 upper layer of acrylics
    [ATTACH]865369[/ATTACH]

    "Painting is a verb"

    #817174

    Gary, it looks as if it worked just fine.

    I guess it would be worth experimenting with and if you still can’t get the smooth stroke you want, you can always try something else!

    I think all art is just one big experimentation – I wonder if we’l ever get to the point where we have total control and mastery over the outcome of every painting!!!

    I like this, especially the contrast of the front yellow trees with the dark green. If I had to find a flaw, I think I’d give just a bit more variation to the distant hills.

    #817175
    llawrence
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        Seems like a good idea, and you obviously got a good result with it. Right now I’m experimenting with something similar, doing watercolor glazes over casein. Working out okay so far, though it does cause some gloss contrasts.

        #817178

        Thanks AbyA. I struggled with how to keep the far hill in the distance, behind the dried tree to the left. It was an unscratched itch.

        Thanks llwarence. I will be interested to see how your experiments turnout. It seems to me that finished work would have to be framed under glass. Would a matte finished glass blend the glossy parts in to rest of the work?

        Gary

        "Painting is a verb"

        #817176
        llawrence
        Default

            Would a matte finished glass blend the glossy parts in to rest of the work?

            I’m not sure—truthfully I had no idea such a thing existed. But I have started to experiment with wax medium as a varnish over casein. Happy with the results so far, and I plan to try it over the mixed medium paintings very soon.

            #817177

            There are some possible long term side effects. Acrylics may look dry in a few hours, but they take up to a few months to cure completely. During that proccess they tend to reorganize their large molecule chains and they Drag up and down in the layers any impurities that may be attached.. that includes other pigments of mediums with less adhesive power than the acrilics. So you might see some changes in the colors in a few months.

            "no no! You are doing it all wrong, in the internet we are supposed to be stubborn, inflexible and arrogant. One cannot simply be suddenly reasonable and reflexive in the internet, that breaks years of internet tradition as a medium of anger, arrogance, bigotry and self entitlement. Damm these internet newcomers being nice to to others!!!"

            "If brute force does not solve your problem, then you are not using enough!"

            #817179

            Thanks Tiago.Dagostini for the advice. Gary

            "Painting is a verb"

            #817172
            Delofasht
            Default

                I did a painting of a dog with Casein under Acrylic, it turned out quite well I thought.

                The color shift Tiago mentions is possible but usually acrylic only does that to dye based inks and paints (the chemical structure in wood that gives it color is similar to dyes and SIDs are a result). It is a reaction of the chemicals used in acrylics reacting with wood to create that effect. Casein uses pigments and in my uses has not produced any color shift in Acrylics layered over it. I did a few studies in acrylic over Casein before determining it would work well for my commissions.

                There is some serious benefit to using acrylic over Casein in terms of compatibility and drying, acrylic is quite flexible and probably shouldn’t be used under Casein though (unless the Acrylics are diluted to wash consistency, no thickness). There are some adventurous people who mix the two mediums while wet, which is probably fine, adding flexibility to the Casein paint. In layers though, it should be flexible over inflexible usually Acrylic over Casein.

                Casein is quite fun to use, and I like how it lightens as it dries, but can be buffed after cured to a rich glossiness that restores the look of it when wet. I used some cold wax medium as a varnish on a few of my works and really like the look of it.

                - Delo Delofasht
                #817180

                “There is some serious benefit to using acrylic over Casein in terms of compatibility and drying, acrylic is quite flexible and probably shouldn’t be used under Casein though (unless the Acrylics are diluted to wash consistency, no thickness). There are some adventurous people who mix the two mediums while wet, which is probably fine, adding flexibility to the Casein paint. In layers though, it should be flexible over inflexible usually Acrylic over Casein.”

                Thanks for the input. I paint small on Gessobord when painting caseins over acrylics. I have not worried about flexibility issue. If I notice a problem, I will eat crow and mention it here. Gary

                "Painting is a verb"

                #817173
                Delofasht
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                    I would consider the “rule” regarding Casein over acrylic more like a guideline really, it is not advisable due to differences in how they handle temperature changes. Especially in particularly hot environments, acrylics have a tendency to expand significantly more than Casein (which is more rigid and less temperature reactive). This sometimes comes up when someone is using a heat gun on the back to remove a sticker or other glued on article that has been attached (like a wood cradle).

                    Of course, for us as individuals painting for ourselves and not for gallery or sales purposes, it probably would never really come up. So I doubt you will find yourself eating crow anytime soon. :)

                    I just like making sure such information is known for people who may find this through a search engine one day.

                    - Delo Delofasht
                    #1426076
                    Artsoo
                    Default

                        can we paint casein over acrylics? I would like to try that I prefer the casein velvety matte finish more

                        #1426132
                        Artsoo
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                            I have a question when you paint casein over acrylics do you need an isolation coat like matte medium or there is not need to use it?

                             

                            also after you are done do you varnish it?

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