Acrylic grounds on oil paintings

Mar Gomez Lobon <info<-a t->artco-services< . >com> writes

>I was recently approached by an artist concerned about the use of
>acrylic grounds on his oil paintings since he was told by someone
>else that he should be using oil priming.  I understand there is some
>debate over whether acrylic 'gesso' grounds are good or not for oil
>painting; however the reality is that they are the most widely used
>grounds for oils by artists nowadays, plus the vast majority of the
>preprimed canvas on the market.  Oil grounds are not so readily
>available as acrylic gesso, so artists may have to prepare them by
>hand, and they take a lot longer to dry.  I would like to know if
>there is any conclusive conservation research on this subject, since
>I haven't been able to find any literature apart from the various
>advice from different art suppliers.  I would like to hear other
>conservators opinions on the subject, should we be advising artists
>to use exclusively oil primings on oil paintings?

While I have not seen many studies exploring the overall failure of
the bond between oil paint and acrylic priming, in 2008, a student
at Queen's University examined the impact of zinc and lead soap
formation at the interface of oil paint and acrylic priming.  The
paintings in the study showed general instability and large flake
losses of oil paint, due probably to the presence of metal soaps at
the interface.  See

    Maor, Yonah
    Delamination of Oil Paint from Acrylic Grounds
    Queen's University Master's thesis, 2008

At the CCQ, we do periodic seminars for artists, sharing
observations and lessons gleaned from the literature and from
various treatments.  We recommend that artists avoid using a zinc
white oil paint layer over an acrylic ground.  We also suggest they
wipe down a commercial acrylic priming with a damp rag to remove any
excess surfactants, and that they add an additional layer of good
quality acrylic priming if needed.  As with all painting materials,
a sufficient amount of tooth is required to achieve a good bond
between the paint and the priming layer.

Michael O'Malley
Centre de conservation du Quebec


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                  Conservation DistList Instance 27:34
                  Distributed: Tuesday, March 11, 2014
                       Message Id: cdl-27-34-002
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