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BY CLIVE PATES
Impasto With Impact
Enjoy the bold expressiveness of impasto with these tips on choosing a palette,
making marks and layering colors.
OIL PAINT straight out of the tube
has a buttery consistency that, when
applied thickly with a brush or palette knife, holds its shape. Artists
use this property to enliven paintings with texture and suggest an
expressive feeling. Applying paint
thickly in this manner, a technique
called impasto, is traditionally associated with oil and, more recently,
with acrylic. Here I’ll concentrate on
the more traditional medium. (For
a brief explanation of how acrylic
impasto differs from oil impasto, see
The Acrylic Difference, page 30.)
The technique is fun to experiment
with, but a consistent use of impasto
can be one of the hardest techniques
to master and can drive realist painters to distraction, especially if they
consider detail to be important.
Controlling Mixtures, Marks
and Harmony
There are three main challenges for
a student of impasto. First are the
various difficulties in controlling
thickly applied oils. For example,
thicker paint can mix in unexpected
ways, creating a muddy paint film.
Working in grisaille (monochrome)
or with a limited palette helps, but
only through experience can you
really learn to deal with the way
thick paint mixes with other paints
or colors.
Fortunately, as you gain experience in creating impasto mixtures,
especially when using a palette
knife (see Learn More Online, page
32), you’ll also become more adept
at placing marks—another control
issue for impasto. Just as a watercolorist preplans the application of
paint, the impasto painter must plan
in order to place marks in a fresh
and articulate way.
With impasto, achieving color
harmony can also be a challenging
“control issue.” Generally speaking, a saturated color palette can
cause a visually distracting clash
of colors, and this tendency is even
more noticeable and harder to control with impasto. One way to deal
with unwanted color combinations
is to use a limited palette—a good
approach for anyone starting out
with impasto. With a tonally close
selection of pigments, such as Indian
red, yellow ochre and cobalt blue, an
artist can mix thicker paint without
any undue clash of chroma. The
close tonal range of colors creates a
natural harmony.
Balancing Technique and Style
Finessing the elusive relationship between technique and style
is the second challenge presented
by impasto. The point where good
painting practice develops into a
unique stylistic approach is hard
to define. With impasto, there are
LEFT: For Redbud (oil on linen, 27½x27½),
from my Gray to Black series, I worked the
impasto broadly and quickly with a painting
knife in order to keep the light and color
fresh.
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The Acrylic
Difference
The use of acrylic paint as an
impasto medium should be
approached in an entirely different
way from the use of oil paint. In general, the advantage acrylic offers
over oil is related to acrylic’s shorter
curing process; acrylic paint layers can be applied over each other
after comparatively short lengths of
time. Without the addition of drying
extenders, however, thicker layers
of acrylic can be problematic. The
reason for this is that acrylic has
a two-stage drying process; in a
matter of minutes, a dry skin forms
on the surface, but an underlying
impasto layer can take several days
to harden. This makes working wet
into wet for any extended period
difficult because the skin of the
preceding layer will tend to tear and
drag over the surface.
In my opinion, the use of drying
extenders defeats the quick-drying
advantage of acrylics, and those
extenders cannot replicate what
I consider the superior tactile
qualities of oil paint. I feel acrylic
is best used in a more immediate
way, with techniques that take
advantage of its short drying time.
Acrylic excels in the creation of
quick, alla prima studies, especially
when they’re painted with additional glazing effects over a lighter
impasto layer.
a number of good, basic practices.
For example, it’s generally accepted
as good practice to build up the
paint surface slowly, sketching with
thinner layers of paint and building gradually to thicker impasto
applications. Also, larger, flat areas
of impasto are hard to work with
and create a barrier to further paint
applications; consequently, applying
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smaller, considered areas of thicker
paint can greatly enhance the success
of an impasto painting.
The manner in which an impasto
artist paints these smaller areas,
however, can become a matter of
style. Splotches of impasto paint that
coordinate and flow into each other
are easy to read; painted marks that
fight against each other can create
unwanted visual distraction, especially when the marks are emboldened with impasto. In an abstract
work, however, discordance might
be beneficial, so technique has to be
set against the needs of the artist.
Impasto naturally inclines itself to
individual expression, but a balanced
approach, in which technique and
experience focus the mark-making
process, helps articulate the image.
Layering for Longevity
The third and perhaps most important challenge with impasto is dealing with conservation issues. Poorly
applied, thicker layers of paint can
create a whole range of problems
within the paint’s surface. The foremost rule in impasto work is that
thicker paint should be applied over
thinner paint. If an artist applies a
thinner layer of paint over a thicker
layer that isn’t completely cured
(dried), the upper layer has a good
ABOVE: This close-up of stress cracks on
a painting’s surface shows what happens
when an artist applies thinner, scumbled
paint washes over a thicker paint layer. The
differing expansion and contraction rates
between the layers create a crackled effect.
chance of cracking because of the
differing rates of expansion and contraction in the two layers (see “stress
cracks,” above).
To complicate matters, there’s
the rule of fat over lean, meaning
that paint with higher oil content
or oil absorption should be applied
over paint with lower oil content or
oil absorption. Certain colors (notably, lamp black) can be a problem
because their pigment particles have
a higher oil absorption index (absorb
greater amounts of oil) and can cure
at slower rates. A layer of paint with
a high oil absorption index, even if
painted thinly in the initial stages,
can cause successive layers of paint
to crack. The addition of linseed oil
in moderate amounts to subsequent
layers of paint can help resolve some
problems, and a working knowledge
of the behavior of the colors on your
palette is always helpful.
Heavy impasto can also sag
and move—in some cases, breaking
away completely from the paint layer
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Impasto Marks
In the close-up details A and B of Cultural Park Study (oil on
linen, 24x24), the scene dissolves into many splotches of paint,
but the coordination and balance of the marks allow them to
work together to form the larger image. With impasto, you
must carefully consider each mark before it’s applied, or you’ll
risk muddying and losing the spontaneity and clarity of the
overall image.
A (close-up)
A
B
B (close-up)
beneath it. Many artists mix in fillers or mediums to stiffen an impasto
layer. Some of these adulterants just
bulk out and add a buttery flow to the
paint but, in most cases, these substances detract from the strength and
longevity of the paint film. To bulk
out and stiffen thicker impasto layers,
I recommend adding small amounts
Learn More ONLINE
For a link to the article “Painting
With a Knife,” by Deborah QuinnMunson, go to www.artistsnetwork.
com/learnmore2015.
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of inert fillers, such as marble dust or
silica. If you can, however, it’s better to paint with no adulterants so
you can concentrate on the painting
rather than the filler or medium.
It’s impossible to learn all the
rules of impasto painting without
hands-on experience and a certain
amount of trial and error. Paint
manufactures design their products
with various additives to balance the
curing rates of different tube colors, and oil paint is a very forgiving
medium, but the thicker you apply
the paint, the more challenges you’ll
experience.
To sum up, impasto painting
can be rewarding, but it also involves
a sharp learning curve for those who
take it seriously. I, like many artists, have learned from experience
what works for my own paintings,
and I recommend trying impasto to
explore the potential of oils. You’ll
find that impasto’s extra dimension of gestural texture lends an
emotional resonance that cannot be
achieved any other way. n
CLIVE PATES has worked as a regional
editor for Fine Art Connoisseur and PleinAir
Magazine. He also lectures internationally,
most recently at Yavapai College–Sedona
Campus in Arizona. Visit his website at
www.clivepates.com.