TECHNIQUES
CRACKED OR CRACKLED PAINT FINISHES
 These
are achieved by producing cracks in a layer of paint,
which exposes a second layer underneath.
Craquelure is the term used for the finish resulting
in hairline cracks in a varnish. The cracks do not
open up and reveal the surface underneath but are rather
like the cracks in the glaze of an old porcelain plate.
Cracked paint finishes and craquelure are two different
finishes. Crackle or the effect of cracked paint will
be described below. As yet, a true craquelure finish
is not consistently obtainable with water-based paints.
CRACKED PAINT EFFECTS:
Paintmakers since time immemorial have been constantly
formulating and re-formulating to make their paints
last longer and longer and most certainly to avoid
cracking. Therefore, when the paint is required to
crack, it is working against what it has been designed
to do. As with anything that is working on the limits
of its specifications, there are some guidelines that
must be followed to ensure the desired results.
PROCEDURE:
Step1:
 The
first coat of paint laid down will be the color that
shows through as the cracks. This first coat should
be a water-based paint such as Matisse Professional
Artist Acrylics Flow or Structure Formula
or, for larger areas, Matisse
Background Color will give the best results. Leave
this coat to dry before going to step
2.
It is possible to omit this coat. If the desired effect is to show the surface
as cracks, the Cracking Medium can
be applied directly to any surface that acrylic paints will normally adhere
to. For example, if cracking on a wood surface and the desired effect is
to have the paint cracking to reveal the woodgrain underneath, skip step
1 and start at step 2 ensuring the surface
is clean and free of oil, grease and dust.
Step
2:
 Once
step 1 is dry, apply MM23
Cracking Medium (water-based).
APPLICATION:
The Cracking
Medium may be applied with a brush, sponge applicator
or roller (either a sponge or short nap roller).
Apply the Cracking
Medium so that it is as thick as possible but
not so thick that it runs when the surface is held
vertically. The Cracking
Medium is designed to be a high-build coat; therefore,
it is very viscous (thick). Do not be overly concerned
with obtaining an even flat surface as the Cracking
Medium has a built-in flow agent which will allow
it to level out as it dries.
SPRAY APPLICATION:
It is possible to thin the Cracking
Medium down with water so that it may be sprayed
through a spray gun for larger areas. The amount
of water used should not exceed 25%. Also keep in
mind that the medium must be at least 1-2mm thick
to work. Always do a test with the equipment to be
used and the dilution rates before embarking on a
large project.
USE APPROVED RESPIRATORY EQUIPMENT. Do not inhale
the Cracking
Medium.
Step
3:
 This
is the coat that cracks to reveal the coat applied
in Step 1. Step
3 must be applied within 12 hours of step
2 drying. The paint used MUST be Matisse
Background Color as the Cracking
Medium has been especially formulated to work with
this paint. The special formulation, unlike some other
brands, allows for different types of cracks to be
achieved and repeated with consistency.
The Matisse Professional Artist Acrylics Flow and
Structure ranges
will not always work as a topcoat with the Cracking
Medium unless they are mixed with MM5
Matt Medium (this is discussed further in Cracking
Metallic and Tube Colors).
When applying the topcoat, it is important not to
re-work areas that have already been covered as re-working
an area can lift the cracking coat and stop the process
(see below for more details).
HOW IT WORKS:
The old methods of cracking using gum arabic and forced
drying were quite unreliable. They relied on the different
drying speeds to crack the paint. The climate had to
be just right and the slightest mistake would result
in the process not working.
The Matisse cracking process relies on a reaction
between the topcoat of Matisse
Background Color and the Cracking
Medium which has been applied below it. Once the
topcoat is applied, the cracking coat below becomes
semi-liquid again and shrinks, taking with it the topcoat.
It is worth noting that the topcoat should be applied
systematically, covering the surface and not going
over an area that has already been covered. As described
before, the paints have been designed not to crack;
therefore, when the Cracking
Medium is trying to shrink and take the topcoat
with it, the topcoat is actually trying not to break
apart.
The thickness of the topcoat will dictate how big
the cracks are. The thicker the topcoat the more easily
it is able to hold together and resist cracking but
when the Cracking
Medium gets its way and manages to crack the topcoat,
it will result in a very large crack. Thus the thicker
the topcoat of Matisse
Background Color, the fewer the cracks but they
will be big ones.
Conversely, if the topcoat is applied very thinly,
the Cracking
Medium will strike less resistance from it and
therefore result in many more cracks but they will
be much smaller in size.
HOW TO ACHIEVE
DIFFERENT PATTERNS:
Following on from above, it can be seen that if the
topcoat were to be applied using a brush and brushing
in the one direction, the overall pattern of cracks
would be in the direction of the brushstrokes. This
is because even though one aims, when using a brush,
to lay down a nice flat coat, in reality if the brushstroke
is studied closely, the topography of the paint has
corrugations in it. These corrugations run parallel
to the drag of the brush.
As described above, the paint will tend to crack at
its least point of resistance or where the paint is
the thinnest. Therefore the thinnest parts in a brushstroke
are the troughs in the corrugations, which in turn
give the elongated cracking pattern.
If a sea sponge is used to apply the topcoat, the
topography becomes more akin to sand dunes; therefore,
the resultant pattern would be more rounded and random.
OTHER INFLUENCES
ON PATTERNS:
The types of cracks obtained depend on the thickness
of the topcoat and the way in which it is applied.
The bottom coat has no bearing on the outcome of the
cracking pattern. The way in which the cracking coat
is applied will not affect the pattern, unless it is
too thin, in which case it just won't work.
The surface on which the finish is to be applied
may have some bearing on the pattern. For instance,
if very large cracks are desired, the topcoat will
need to be applied very thickly. It will be necessary
to have the surface horizontal as the weight of the
paint may run and pull the cracking medium if the surface
is vertical.
On frame mouldings or 3-dimensional pieces the paint,
as it cracks, will tend to sink to the lower surface
due to gravity. This may leave edges or sharp points
exposed and make the piece look contrived.
If the artist is new to this finish, it
would be prudent to do some tests on an old sheet of
cardboard etc. before a large project is attempted.
FINISHING OFF:
 It
is not necessary to varnish the
cracking finish unless it is to be used on utility
items with a lot of wear and tear or if it is to reside
outdoors.
The cracking medium may also give a higher sheen to
the first coat (i.e. the cracks) than the topcoat.
A varnish may be used to even out the different sheen
levels as well as protecting the finish from water
and some wear and tear.
Use only a solvent-based varnish such as MM14
Final Varnish Gloss Finish or MM15
Final Varnish Matt Finish. DO NOT use a water-based
varnish as a final coat as it may crack.
CRACKING METALLIC
AND TUBE COLORS:
As previously mentioned, the Matisse
Cracking Mediums are designed to work only with
the Matisse
Background Colors. However, it is possible to
use Matisse Professional Artist Acrylics in the Flow or
Structure Formula
as a topcoat. To use the Structure or Flow,
which includes the metallic
colors of gold, silver, copper and bronze, mix
the color with equal parts of MM5
Matt Medium. This mixture may then be applied
over the Cracking
Medium in the way described above. The MM5
Matt Medium gives the correct ingredients needed
to activate the Cracking
Medium while reducing the amount of binder in
the paint allowing the Cracking
Medium to work.
CRACKING VARNISH:
An interesting effect over a painted piece or even
a print is that of cracked antiquing. It is possible
to crack a water-based varnish.
Omit step 1 and start
at step 2 as described
above, applying the Cracking Medium over the piece
or print.
Step 3:
As a topcoat use one of the following - MM6
Polymer Matt Varnish water-based, MM7
Polymer Gloss Varnish & Gloss Medium, MM11
Satin Varnish or MM19
Poly-U-Gloss Varnish.
Apply the varnish as a topcoat, as per the directions
above, to obtain the desired types of crack. The result
will be a clear varnish with cracks in it. As the Varnish
is clear and the Cracking
Medium is clear the cracks will be hard to see,
so the next step is to antique the
piece so that the cracking stands out.
Leave the piece for at least 48 hours after it has
finished cracking as the antiquing process can re-start
the cracking if it is not fully dry.
Step 4:
Using a rag soaked in MM20
Water-Based Patina, add a little dab of Matisse
Flow Formula raw umber and wipe this over the
surface. The raw umber should catch in the cracks
and "dirty" the piece up, giving a time
worn look (see the section on antiquing for more
details).
FAUX ANTIQUE GILDING:
One way of producing a beautiful old cracked gilded
frame is to gild a frame and wait 200 years. Another,
much quicker, way is to imitate the finish. This is
done via a series of steps set out below:
Step 1:
Basecoat the project with Matisse
Background Color (the colors most often used
are china red, burgundy and pale beige.)
Step 2:
As above, apply the Cracking
Medium and leave to dry.
Step 3:
As described above, mix Matisse
Flow Metallic Light Gold with MM5
Matt Medium in equal parts and apply with a sea
sponge or brush by dabbing in a perpendicular motion
to the surface. Leave to dry for 48 hours.
Step 4:
Antique the project as per step
4 above.
Presto! One antique faux gilded frame. With a little
practice, it is possible to achieve a finish that is
uncannily close to the real thing. For instance,
keep in mind that gold leaf is usually applied in sheets of 5 to 10 cm
so every 5 or 10 cm if the gold is applied a little
thicker, it will resemble
the overlapping of the sheets. |
