What is Lightfastness?

What is Lightfastness?

Lightfastness refers to how well a paint's color resists fading when exposed to light, especially sunlight. Paints with high lightfastness keep their colors bright and accurate over time, while paints with low lightfastness can fade or change color quickly. This happens because ultraviolet (UV) rays from light can break down the chemical structure of pigments in the paint.

Lightfastness is simply how well a paint resists fading when exposed to light. Think of it as sunscreen for your artwork! When light hits paint, a chemical reaction called photodegradation can happen, which might cause your colors to fade or change over time. You need lightfast paints if you want your artwork to stay vibrant for years.

Lightfastness is rated using systems like ASTM (American Society for Testing and Materials), where:

• ASTM I means excellent lightfastness (ideal for permanent art).
• ASTM II means very good lightfastness.
• ASTM III means it is not sufficiently lightfast for professional use.

For example, if you're painting something that will hang in a sunny room or be displayed outdoors, you'll want paints with high lightfastness to ensure your artwork doesn't fade over time.

What Does Archival Mean?

Archival materials are designed to last a very long time without deteriorating. For paints, “archival” means they meet museum-quality standards for durability and stability. This includes being acid-free and chemically stable, so they won't damage or degrade the surface they're applied to.

Archival paints are ideal for creating artwork intended to last generations. However, being archival doesn't always mean the paint is lightfast—some archival materials might still fade if exposed to strong light over time.

Why Should You Care?

As an artist, you want your work to look as beautiful years from now as it does today. Here's why these terms matter:

• Longevity: High-lightfast and archival paints ensure your artwork doesn't fade or deteriorate over time.
• Professional Quality: Using durable materials shows you care about quality if you sell or gift your paintings.
• Creative Choices: Some pigments with lower lightfastness might offer unique colors, but you'll need to use them wisely—perhaps in indoor settings or temporary projects.

By choosing paints with good lightfastness and archival properties, you're investing in the future of your art! Let's compare two popular paint brands, Liquitex and Golden.

Liquitex vs. Golden: Lightfastness Comparison

Some artists have reported that Liquitex Heavy Body paints may fade more over time compared to Golden Heavy Body or other professional-grade acrylics like M. Graham and Winsor & Newton Professional Acrylics. However, this depends on several factors:

1. Pigment Load and Quality

• Liquitex Heavy Body acrylics are generally well-regarded and have a decent pigment load. Still, some artists have observed that their lightfastness and color intensity may not hold up well over decades, particularly in specific colors.
• Golden Heavy Body Acrylics are often preferred for their higher pigment concentration and reliable archival quality, with many artists considering them superior for long-term color retention.
• Brands like M. Graham and Winsor & Newton are known for strong pigmentation and permanence, often rivaling Golden.

2. Lightfastness Ratings

• Both Liquitex and Golden provide ASTM lightfastness ratings on their colors. However, some Liquitex colors, particularly those using modern organic pigments or convenience mixtures, may not perform as well over decades.
• Golden's lightfastness ratings tend to be more consistent across their range, and their transparency about pigment load gives artists more control over longevity.

3. Additives and Binder Quality

• Liquitex has been reported to have slightly more binder and fillers, which can lead to more noticeable fading over time compared to Golden.
• Golden heavy body acrylics have excellent reputations for lightfastness. They're described as offering “excellent permanency and lightfastness”. Golden doesn't add fillers, extenders, or dyes that might affect how long the colors last.
• Some artists have noticed that Liquitex's matte and satin mediums might also contribute to slight dulling over time.

4. Artist Anecdotes and Reports

• Some long-time acrylic painters have observed that Liquitex colors may shift slightly in vibrancy or become more muted over the years, particularly when exposed to direct sunlight.
• Comparatively, Golden's colors have been noted to retain their richness and depth longer under similar conditions.

5. Testing & Longevity

• Liquitex's lab tests still rate their paints as archival, but independent artist tests suggest that Golden retains saturation longer when paintings are exposed to UV light over extended periods.

Both brands are considered professional-grade and take similar approaches to ensuring their paints resist fading. Both companies also provide detailed information about the pigments used in each color, which helps artists make informed choices.

Factors to Consider When Choosing Professional Heavy Body Paint

• Pigment load: Higher pigment concentrations result in more vibrant, long-lasting colors.
• Consistency: Heavy body acrylics have a thick, buttery texture that holds brush strokes and knife marks, making them ideal for impasto techniques.
• Viscosity: These paints offer good surface drag, allowing for excellent handling and blending with increased open working time.
• Color range: Some brands, like Liquitex, offer a wide selection of colors, including special formulations like cadmium-free, iridescent, and fluorescent options.
• Lightfastness: Professional-grade paints often use pigments rated ASTM I or II, ensuring your artwork remains vibrant for 50+ years in gallery conditions.
• Versatility: Heavy body acrylics can be used on various surfaces and are compatible with other acrylic products, allowing for diverse techniques.
• Finish: Depending on the pigments used, different colors may have varying levels of opacity and sheen, from matte to satin.
• Archival quality: Professional heavy body acrylics are typically formulated to be archival, ensuring your artwork's long-term stability and durability.

Final Thoughts

Based on all available information, both Liquitex and Golden heavy body acrylics should provide excellent durability when:

• You choose colors with good lightfastness ratings
• You apply proper varnish for UV protection
• Your paintings are displayed in appropriate lighting conditions

There isn't conclusive evidence showing that one brand consistently fades more than the other over time. Both are professional-grade paints that should serve you well for many years.

If you're extra concerned about a particular painting lasting as long as possible, you might consider:

• Choosing Golden if a slightly higher pigment load is important to you
• Checking the specific lightfastness rating of individual colors (regardless of brand)
• Applying a quality UV-protective varnish as a final coat

Water Dilution Guidelines

Another consideration is how much water you use with your paints as you apply them to the canvas.

• When thinned with water or medium, the paint can lose color intensity and strength.
• Technical advisors from Liquitex recommend adding no more than 25% water, as adding more “will start leading you towards an underbound, weakened paint film.”
• Golden Paints does not set a strict maximum limit for adding water to its heavy body acrylics but provides guidelines to ensure durability and adhesion. Their testing shows that even at high dilution levels, such as a 1:20 paint-to-water ratio, adhesion remains strong when applied over properly primed surfaces like those coated with Golden Gesso.
• For thinning beyond a 1:20 ratio or when increased durability is needed, Golden suggests adding at least 1 part of their acrylic medium (e.g., Fluid Matte Medium or Gloss Medium) to 10 parts water before further dilution.

My Personal Take

As someone who's been painting with acrylics since they first appeared, I find Golden Heavy Body to be a reliable, professional paint. Every brand has its quirks, and understanding these common complaints can help you decide if Golden is right for your painting style.

You'll probably enjoy Golden Heavy Body if you love impasto techniques and thick applications like the old masters of yesteryear and their oil paints.

Remember, the “best” paint is always the one that works best for YOUR painting style and techniques!

Your Personal Art Coach,
Ginger