If the mural is not an existing structure, but will be constructed
specifically for your artwork, carefully consider the choice of
building materials to be painted. For example, there are many
plywood grades available. MDO plywood (Medium Density Overlay),
often referred to as "sign painters board", is a high-quality
plywood that is made to be used outdoors. It could also be attached
to a wooden, metal or brick wall before painting a mural. This
would offer the artist a surface that is clean, smooth and can
be painted indoors in the studio, rather than on a scaffold at
the mural site.
Painting an Existing Surface
If factors dictate painting directly onto a pre-existing surface,
preparation is a major factor in the longevity of the mural.
Surface Cleaning Considerations
The artist must be concerned with the nature of the surface
to be painted. If the surface is already painted, then consider
what kind of paint it is and its physical condition (the artist
should realize that any surface that still has the previous coating
on it will not be as permanent as one that has been completely
stripped and freshly coated). If the paint is a water-based polymer,
chances are good that the GOLDEN paints will adhere sufficiently.
If it is a high gloss oil paint (or of unknown materials), then
it must be abraded (or removed) for good adhesion. If the existing
paint film is deteriorating, then it is best to have it removed
(sandblasted, power-washed, scraped, etc.). It is critical to
wash any painted surface, even a newly painted surface, with soap
and water prior to application of acrylic products. A major coatings
manufacturer states that as much as 80% of all coatings failure
can be directly related to insufficient surface preparation.
Previously painted high gloss surfaces can be cleaned and dulled
in one step by using a household abrasive cleaner. Wash off completely
with clean water.
Mold and Mildew
Mold and mildew must be removed by hand scrubbing with a mixture
of 1 part household bleach to 3 parts water. CAUTION: Never
add ammonia or ammonia-based cleaners to bleach! Wear goggles
and protective equipment while cleaning. After scrubbing with
a brush, allow the solution to sit on the surface for 10 minutes
before thoroughly rinsing off with clean water.
Cracks and Grooves
If there are cracks and grooves in the substrate, the method
for filling and smoothing these gaps will depend on the nature
of the substrate itself. Artists should consult an area architectural
coatings store for recommendations on the best product available.
Priming the Surface
Once the surface has been cleaned, a primer coat will give
better adhesion for the paint.
One key feature to look for in a primer is whether or not it
can be painted over by latex (waterborne) paints. This should
ensure that the primer will be a compatible surface for the adhesion
of GOLDEN waterborne acrylics.
To determine the best primer1 for a specific
surface, we suggest artists contact a local supplier of architectural
coatings. Such companies have extensive experience with priming
the broad spectrum of building supplies, and typically have specific
primers for the surface the mural is to be painted on. Their recommendations
will also take the environmental concerns of the area into account.
We have found that architectural and maintenance paints are competitively
priced, meaning that a product that costs more than a similar
product will typically perform better as well.
When painting on brick, concrete, or other masonry surfaces,
it is recommended to also use a Masonry Conditioner that can be
purchased from a commercial coatings supplier.
Acrylics are some of the most durable paints for exterior
Acrylics are some of the most durable and accessible paints for
exterior application, used by many artists for painting murals
due to their lightfastness and weather resistance. They also form
an excellent bond to masonry or cementous surfaces. Oil paints
are a poor choice for painting on these surfaces since the alkalinity
of concrete can destroy alkyd or oil products. Ethyl-Silicate
paints form an excellent and permanent bond with brick or concrete;
however, this system can be time-consuming and costly, and good
working knowledge of the system is required as well. Solvent-based
enamels are a good choice for durability, but manufacturer's pigment
considerations are usually not the same as with a high-quality
artist's acrylic paint.
Golden Artist Colors produces several lines of paint that
can be used for mural work.
Selecting which type of paint to use is dependent on each artist's
style and the surface to be painted. GOLDEN Heavy Body, Matte,
MSA, Fluid and Airbrush Colors can all be used for mural work.
The artist must determine if the texture will influence the way
he or she paints. For example, if painting on brick, it will be
tough to get a smooth line brushed on with the Heavy Body Colors
as is. They need to be thinned with GAC 200 (which also increases
film hardness and potential durability) or the artist may consider
switching to the Fluid Colors. The thinner consistency will allow
the paint to flow into the crevices of the brick. (Refer to the
chart below for selecting a suitable paint line).
GOLDEN PAINTS SELECTION CHART
this Quick Reference Chart for choosing GOLDEN Acrylic Paints
for Mural Use.
Note: Mixing is recommended with the GAC 200 to increase
adhesion and durability, which will thin thicker viscosity products.
Choosing the Right Colors
Color selection is especially important to minimize fading.
The GOLDEN Pigment Identification Chart lists the relative lightfastness2
and permanency ratings of all our colors. For maximum longevity,
we recommend using only colors with a lightfastness rating of
I and a permanency rating of Excellent. Please note: Cadmium pigments
should not be used outdoors, as premature fading will occur.
GOLDEN Suggested Color List
for Exterior Murals
Although GOLDEN uses only the most permanent pigments available within each chemical classification, we have compiled this list of the best pigment choices for use on an exterior mural. Application of isolation coats and a suitable varnish or topcoat is highly recommended.
BEST PIGMENTS - The most stable GOLDEN colors for exterior use.
Bismuth Vanadate Yellow
Burnt Umber Light
Chromium Oxide Green
Chromium Oxide Green Dark
Cobalt Titanate Green
Iridescent and Interference Colors (except Iridescent Bright Gold)
Manganese Blue Hue
Phthalo Blue GS
Phthalo Blue RS
Phthalo Green BS
Phthalo Green YS
Pyrrole Red Dark
Pyrrole Red Light
Terre Verte Hue
Transparent Brown Iron Oxide
Transparent Red Iron Oxide
Transparent Yellow Iron Oxide
Van Dyke Brown Hue
GOOD PIGMENTS - Stable colors,
but avoid thin layers or glazes for
minimal color shift.
Cerulean Blue Deep
Naples Yellow Hue
Hansa Yellow Opaque
Increasing the Durability of the Paint System
Although GOLDEN Acrylics are optimized for traditional easel
painting, the acrylic resin is somewhat soft for mural work, and
should be modified with a harder acrylic medium to maximize durability.
Adding GAC 200 also reduces the pigment load of the paint mixture,
making the paint more binder rich, which extends exterior lifetime.
This is especially important if the artist chooses not to topcoat
with a varnish. To improve the exterior durability of the paints,
blend in 1 part GOLDEN GAC 200 for every 2 to 4 parts paint.
For exterior spray application, using GOLDEN Fluid Acrylics thinned
with Airbrush Medium will be the most durable option. GOLDEN Airbrush
Colors can also be used, but they should be blended with GOLDEN
Airbrush Transparent Extender and given a protective finish to
increase durability. In spray application, the GAC 200 is not
practical to use as it will thicken the paint, and interfere with
sprayability. Another approach would be to topcoat the Airbrush
Colors with a sprayable isolation coat using a 2:1 mixture of
GAC 500:GOLDEN Airbrush Transparent Extender.
FINISHED MURAL PROTECTION
Murals and Architectural Applications
Any paint or topcoat applied to a building, including interior or exterior walls, is considered an architectural coating and subject to regulations limiting the amount of VOC’s (Volatile Organic Compounds) a product may have. Murals painted directly onto these surfaces, therefore, will fall under the same guidelines and all paints, mediums, and varnishes being used will need to comply with the same rules. Containers that are 1 Liter (1.05 Quarts) or less in size, however, are currently exempt from these requirements.
Murals Painted Directly onto Architectural Surfaces
PLEASE NOTE the Following Restrictions
- Gallon sizes of our standard MSA Varnishes and Acrylic Glazing Liquid are prohibited in the United States for architectural applications, including interior and exterior murals painted directly onto walls and ceilings.
- Quart containers of our standard MSA Varnish and Acrylic Glazing Liquid are allowed and can be used. The rate of coverage for these products is approximately 75-150 sq. ft. per quart, depending on the type of substrate and method of application.
- Solvents needed to thin standard MSA Varnishes might be limited or prohibited by similar VOC requirements.
- Always check local and state VOC regulations as these may include additional restrictions.
Special VOC--Compliant MSA Varnish and Solvent
The following products are VOC compliant and can be used for murals painted directly onto exterior and interior walls, ceilings,and other architectural surfaces .
Please Note: They are NOT available through retailers. These are custom products and MUST be ordered directly from Golden. Please call Customer Service at 800-959-6543 / 607-847-6154 for pricing and availability.
- MSA Varnish - Mural Formula (Semi-Gloss), Product #: CPWMV01
GOLDEN has formulated this to be VOC compliant in the Graphic Coatings category, < 500 g/l, and applicable for interior and exterior murals. The standard MSA Varnish products are not VOC compliant and therefore are not recommended for such applications. This varnish cannot be thinned with standard paint thinners, as they increase VOC beyond limit, and should only be thinned using the CPWMV02 MSA Mural Formula Solvent to maintain VOC compliance.
- MSA Solvent - Mural Formula, Product # CPWMV02
This solvent is VOC exempt and is used to thin the CPWMV01 MSA Varnish - Mural Formula (Semi-Gloss) for application and while maintaining VOC compliance. Typical additions are 1 part by volume of MSA Mural Formula Solvent to 2-3 parts MSA Varnish - Mural Formula (Semi-Gloss) to thin varnish to proper application viscosity.
Murals Painted onto Canvas, Panel, and Other Supports
- Currently there are no restrictions for murals completely painted and varnished on an independent support which is then mounted onto an architectural surface.
Call or email Technical Support for additional information or assistance.
A final topcoat gives the mural more durability from the
The mural artist has a few choices on how to provide additional
protection to the finished mural. One option is to apply an artist-quality
varnish that is removable with various solvents, allowing for
graffiti removal and general maintenance. GOLDEN MSA Varnish w/
UVLS is such a product, and more complete application information
is provided below.
Another choice for protecting the mural is to use some of the
various graffiti-resistant finishes that are commercially available.
These range from protective wax coatings that are removed with
hot water to the 2-component, solvent-based polyurethane coatings.
They tend to have excellent chemical resistance, so that graffiti
can be fairly easily stripped off without harming the coating.
They also have excellent weatherability, and thus require less
maintenance than some of the other choices. As we have not thoroughly
evaluated these systems, we suggest you get all the information
required from the manufacturers, and/or any mural groups that
may share previous experiences, to determine the best choice for
your specific application.
Application recommendations for GOLDEN
MSA Varnish w/ UVLS:
We recommend a 2-step system, the first being a permanent isolation
coat, followed by GOLDEN MSA Varnish, a removable varnish. The
function of the isolation coat is to physically isolate the paint
from the removable varnish (which makes varnish removal much easier
and safer to the paint surface). An isolation coat also develops
a thicker layer of acrylic, which will give better protection
and durability and serves to unify the acrylic paint layer.
- Isolation Coat Application
Choice of isolation coat should depend upon the artist's
application method. Another consideration is the surface texture,
as brush-applying the isolation coat and varnish over a highly
textured surface can generate foam in the isolation coat. For
spray application, we recommend a 2:1 mixture of GAC-500 to
Transparent Airbrush Extender. For brush application, we recommend
a 2:1 mixture of Soft Gel Gloss to water.
- Varnish Application
IMPORTANT: If applying the varnish to a mural painted directly on a wall, ceiling, or similar surface, read
the earlier section on Murals and Architectural Applications
After the isolation coat is applied and has thoroughly dried
(1-2 days, but no more than 1 week for maximum performance),
GOLDEN Mineral Spirit Acrylic (MSA) Varnish can be applied.
The MSA Varnish w/ UVLS is an excellent choice as a protective
finish. This product provides a tough, durable surface that
increases resistance to moisture and pollutants. The UV stabilizing
system will serve to reduce the destructive potential of ultraviolet
radiation from the sun, thus enhancing the life of the system.
This varnish is removable in mineral spirits, turpentine and
various aromatic solvents, which is a useful property for either
graffiti removal or maintenance purposes. Spray application
is recommended (1-3 coats).*
Note: Breathability is important to the successful adhesion
of acrylic products. If a mural encompasses an entire wall made
of a masonry product, it is advisable to apply thin coats of MSA
Varnish. This will allow interior condensation and evaporating
solvents and out-gassings to escape (some artists recommend leaving
an uncoated breathing space near the edge of the mural as well).
If this is not done, it may lead to premature adhesion failure
between the coatings and the surface.
GOLDEN only recommends its MSA Varnishes for exterior work, NOT
the Polymer Varnish. Polymer Varnish does not have the same exterior
durability as the MSA.
and humidity should be considered during application.
Ideally, the temperature
during application should be between 65°F and 75°F. Higher temperatures
can affect application, especially the evenness of the paint
films, as they will dry much more quickly. Colder temperatures
can harm the film formation of practically all of the coatings,
and the absolute minimum temperature is 50°F. Caution should
be taken at temperatures approaching this threshold.
- Precipitation, Humidity and
Avoid painting in adverse
weather conditions, such as rain and fog. This addition of moisture
can effect the drying times and will re-introduce water back
into recently dried paint films. It is especially important
to allow proper drying/curing time between the isolation coat
and the varnish layer. Trapped moisture can severely hinder
adhesion, and can cause clouding of a clear layer. It should
also be noted that sufficient drying time should be allowed
between washing the surface and the initial primer or conditioner
coats. Architectural coating manufacturers recommend waiting
30 days after washing concrete and cinder-block surfaces under
normal drying conditions.
High humidity can also effect the
murals drying times similar to the conditions cited above
for precipitation. As the relative humidity climbs above 70%,
more caution needs to be taken.
1Primer - a coating that seals and prepares
the surface to accept the subsequent paint layers.
2Lightfast - ability to withstand color change
due to exposure to light.
Use this Mural Procedure
Quick Reference to decide course of action.
The above information is based on research and testing done by
Golden Artist Colors, Inc., and is provided as a basis for understanding
the potential uses of the products mentioned. Due to the numerous
variables in methods, materials and conditions of producing art,
Golden Artist Colors, Inc. cannot be sure the product will be
right for you. Therefore, we urge product users to test each application
to ensure all individual project requirements are met. While we
believe the above information is accurate, WE MAKE NO EXPRESS
OR IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE, and we shall in no event be liable for any damages (indirect,
consequential, or otherwise) that may occur as a result of a product