Choosing the Right Pigments

Choosing the right paints can be tricky because of so much variability across manufacturers. Lightfastness is not the only metric to look at when evaluating paint performance outdoors. Murals challenge paint films with more extreme conditions, many which would rarely be present for an indoor easel painting at a given time. Paint films will often experience high temperatures, exposure to moisture and humidity, moss, bacteria and fungi, while also gradually accumulating carbon monoxide and other chemical pollution in the air. Murals can be exposed to caustic materials, harsh solvents, and purposeful damage, which is why choosing the right pigments also require artists to properly prepare walls, and consolidate thoroughly.

When an artist can document their paint palette, it is important to include the manufacturing date of the paint, the maker, and any pigment information included on the packaging. For situations where the mural must absolutely last, use a reputable brand like Golden Artist Acrylics. 

Economical paints often include opacifiers, formaldehyde and other harsh preservatives, and can even include inconsistent paint manufacturing, which can affect the longevity of paint binders.

Muralists will struggle to find a balanced Titanium White that has high tinting strength and is also well manufactured. It might be a surprise to some muralists that the manufacturing process of Titanium Dioxide as a paint pigment varies by source and the differences can dramatically impact the longevity of a mural.

Finding substitutes for Cadmium paints, which were historically thought to be lightfast for outdoor murals, can be a challenging task but not impossible with modern synthetic pigments. Artists will find small variations in temperature, but often the biggest difference is in the opacity of a paint. Depending on your painting style, this can be an advantage or disadvantage. 

A reputable paint manufacturer will test the longevity of their pigments by conducting longterm exposure tests.  

 

SPARC's Recommended Paints and Pigments

 Recommended Paint/Pigment Replacement of...
Hansa Yellow Opaque Cadmium Yellow Medium
Diarylide Yellow Cadmium Yellow Dark
Bismuth Vanadate Yellow Cadmium Yellow Light 
Light Bismuth Yellow Cadmium Yellow Primrose
Pyrrole Orange Vat Orange or Cadmium Orange
Pyrrole Red Cadmium Red Medium
Quinacridone Red
Pyrrole Red Light Cadmium Red Light
Naphthol Red Medium
Quin Magenta
Permanent Violet Dark
Dioxazine Purple
Quinacridone Violet
Quinacridone Burnt Orange
Phthalo Blue Red Shade
Phthalo Blue Green Shade
Ultramarine Blue
Phthalo Turquois
Phthalo Green Blue Shade
Jenkins Green
Cobalt Teal
Chromium Oxide Green
Mars Yellow
Yellow Oxide
Red Oxide
Burnt Umber
Yellow Ochre
Raw Sienna
Raw Umber
Burnt Sienna
Mars Black
Titanium White
New Suitable Colors for Murals
Benzimidazolone Yellow Medium
Benzimidazolone Yellow Light