Cracking
Cracking
occurs in most antique paintings. They can begin to appear on the
surface of a painting in as little as twenty-five years. Many
Picasso's on display in museums today have long since begun the
cracking process. 
But why do paintings crack? To answer this
question we must understand the construction of an oil painting. An
oil painting on canvass is typically composed of four layers of very
different material sandwiched together. First there is the 'support'
another term for the canvass itself. Applied over that is a layer of
gesso sometime called the 'ground'. This is the actual surface the
oil paint will be applied to.
Originally gesso was composed of
powdered gypsum and a binding agent or glue. The next layer is the
oil paint itself, and finally a coating of varnish is applied after
the oil paint becomes dry.
So here you have four layers of
differing material applied one layer upon the other in a relatively
short space of time. But the fact is that these layers are going to
remain together permanently, and from a technical standpoint each
layer, although appearing "dry" still have a long way to go until
each one becomes 'technically' dry. This is a process that many
experts believe will take at least twenty-five years.
External effects such as heat, light, humidity, or
the lack of it will all have an effect on the drying out of the strata.
Keeping in mind that each layer is composed of a different material, they
each undergo physical and chemical changes unique to their composition.
The result is that stress will develop between the various strata as each
layer reacts to the external conditions in it's own way. As heat and
humidity change some layers will contract and others may expand at their
own rates. In time this stress between the layers will manifest itself
through the strata as a crack.
|
Today, cracks in oil paintings
are acceptable to the connoisseur and are even considered part of
the overall 'charm' so long as they are not disturbing. Occasionally
an antique painting may display wide disfiguring cracks know as '
alagatoring'. When this occurs the only recourse is for the
restoration expert to paint them out.
Genuine cracks,
easily recognizable to the trained eye can also be interrupted as a
sure sign of age and even authenticity. Genuine cracks in antique
oil paintings display definite characteristics. First of all if
the painting is held on an angle to the eye one would see that genuine
cracks generally 'stand up' or are raised slightly along the crack
line. Another point of interest is that cracks occur in
characteristic patterns. A common pattern often observed is that of
a circular effect. One circular line of cracks within a larger
circle, very much resembling a spider web. Another point is that one
crack line will always connect to another crack.
Generally speaking there
aren’t any 'loose ends'. Another common pattern is long straight
or gently curving lines. These are often found running diagonally across
the corners of the painting. Cracks often do not occur uniformly
throughout the surace of a painting. The varying thickness of the
strata can have a distint effect on the 'clustering' or density of
cracks in any given area of the painting. But the characteristic
patterns will still be evident.
The challenge for the reproducer
then is how to create cracks, with all these distinct
characteristics in a 'modern' oil painting. The answer is not in
baking the painting in an oven, which will only blister the surface.
And, the answer is defiantly not found in some commercial substance
sold to induce' cracklure' commonly used by artisans. This type of
crack is only disturbing to the eye but instantly recognizable to
the trained eye.
I have spent
years studying the problem, and developed a method that causes cracks to
form in my paintings in their natural patterns. The only way this can be
achieved is by setting up all the conditions and external factors that
cause cracks to occur naturally, but in an accelerated time frame. My
method can reproduce exactly the pattern and evolution of cracks that
would normally take decades to develop.
"Crack pattern of an actual antique painting"
"Crack pattern from one of my paintings"
"Crack pattern artifically iinduced"