What is lightfastness and why does it matter?

When you’re working on a painting or drawing, it’s important that the colors you use don’t fade over time. The last thing you want is for your hard work to slowly disappear over time because the mediums you chose scored low on the lightfastness ratings. What is lightfastness? Lightfastness (also referred to as Archival or Permanence) is a property of colorants that determines how resistant they are to fading when exposed to light. That means that if you use lightfast paints and pencils, your artwork will be preserved for years to come.

What does lightfastness mean for artists and their artwork?

Lightfastness means that the light your artwork absorbs won’t cause it to fade. That’s why lightfast paint is an essential ingredient for artists working on long-term projects, especially those involving light. Light can have a negative effect on pigment colors, making them fade over time.

As light passes through the transparent layers of oil or acrylic paint, parts of it are absorbed by the pigments in different ways. Some colors only absorb light at certain wavelengths causing them to undergo chemical changes which lead to fading color appearance or even color change altogether.

The effects of light are cumulative so if you leave your paintings exposed to light every day, they will eventually fade faster than if you left them out for just a few days each month.

This can also apply to pencils and other mediums not just oil or acrylic paints. Some pigments in pencils deal with light much better than others, they have a better lightfastness rating.

How can you tell if a particular paint or pigment is lightfast?

The lightfastness ratings are actually printed on the label or packaging of most art supplies. You can also find lightfastness ratings online, usually on the website where you bought your paint or pencils.

If lightfastness ratings aren’t readily available for a particular color, you can do lightfastness tests yourself to make sure it will meet with your standards.

You need to expose 3-4 drops of paint to sunlight or another bright light source for several hours then compare that sample to another drop of the same color that has not been exposed.

While the changes may be slight, if you train your eye to notice the differences you can see in no time at all which paints and pencils have better lightfastness.

What is a lightfast rating?

If lightfastness ratings are given in the form of an ASTM lightfast rating it means that scientists have done lightfastness tests according to these standards.

This is also called a fade scale, A-series or archival series. The letters stand for: B= Blue, C= Clear/Transparent, O= Opaque and T=Tint. There are also five numbers assigned to each color’s lightfastness rating. The larger the number, the better resistance to light it has.

For example A(8) is very good lightfastness while F(3) is poor lightfastness. So in summary, the larger the number the better it holds up over time.

Have a read of the article below if you wish to understand how to read a paint tube label and see how lightfastness or permanence is documented.

HOW TO READ A PAINT TUBE

How will lightfastness affect you as an artist?

If you’re like most artists, lightfastness is probably something you’ve never heard of and don’t think about. But lightfast colors are important because it’s what will be sitting on your table or easel for months to years at a time.

You want lightfast paints and pencils so your hard work doesn’t fade away over time.

If you buy lightfast paints and use lightfast pencils , your artwork will last for many years to come, even if it’s hung in direct sunlight all day every day (which you should avoid anyway because it can affect the surface such as paper or canvas).

Are all paints and pigments created equal in terms of how long they last?

Not all paints and pigments have the same level of lightfastness which is why many brands release a lightfastness chart or rating for their paints and pencils.

This helps artists choose lightfast art supplies that will keep the colors they chose true to life for as long as possible.

You can find lightfastness ratings on paint tubes or paint charts that you can print out and take with you when shopping for lightfast pencils, lightfast watercolors, lightfast acrylic paints, lightfast gouache, lightfast pastels, lightfast oil paints and more!

What colorants are used to make artist-quality lightfast paints?

Lightweight Titanium Dioxide, Phthalocyanine Blue Pigment, Lithol Red, Carbon Black (and similar) pigments are often used in high quality professional light fast brands of oil paint.

Many manufacturers also use less toxic ingredients like Micaceous Iron Oxide, Lead Tin Oxide, and Synthetic Iron Oxide rather than lead based light fast paints.

How lightfast are lightfast products?

As a general rule, you can safely expect lightfastness ratings of “excellent” on oils, gouaches, watercolors, lightfast colored pencils, lightfast pastels, lightfast markers, lightfast ink pens and other artist quality paint supplies.

Keep in mind that all brands of any medium don’t always offer the same lightfastness rating. Cheaper brands may not be as light fast as professional or more expensive brands tend to have better lightfastness due to the fact that they may use higher quality materials in their mediums.

What can you do to protect your artwork from fading over time?

There are many ways to protect your artwork from fading over time but these few simple methods are:

  • Use lightfast paint supplies
  • Prevent light from reaching your artwork by placing them in light tight containers or by hanging them up. This light will fade your light fast paint supplies overtime, so it’s best to keep light away from them as much as possible.
  • Use UV filters on open windows and store paintings out of direct sunlight.

These relatively small precautions can increase the life expectancy of your artwork tenfold.

What things can do if you can’t afford lightfast materials?

Although lightfast materials are the number one choice for protecting your artwork, there are other ways to maintain the vibrancy of your color.

It’s important to use a pigment fixative or other lightproof mediums if you can’t afford lightfast supplies. Pigment fixatives are light resistant and will keep your colors more vibrant and help resist fading.

And as mentioned earlier, frame your works with UV protected glass or perspex, don’t hang or display works in direct sunlight and keep them away from extremes in temperature such as very hot spaces or very cold ones and keep them away from humidity and mold.

Considering lightfastness as a hobby artist

This can feel like a hassle if you are just a hobby artist, but it’s important to take note of the lightfastness ratings of your mediums. Just as you wouldn’t choose to paint with an oil that will yellow and crack as time passes, you should avoid low lightfast pigments if possible.

Even the best lightfast paints and pencils won’t last forever, but they’re much better than their lower lightfast counterparts. 

Consumers today who don’t keep lightfastness in mind run into problems where their artwork starts to fade and discolour over time, so if this is something you want to learn more about it might be valuable research for your art career!

Considering lightfastness as a professional artist

It’s important to think about lightfastness as an artist for a few reasons. Professional artists often work under bright light, and sometimes even the light from a window or lamp can be too much for some low lightfast artworks!

When light falls on a painting, it causes the pigments to fade away gradually over time. If this happens before you sell/commission your artwork, you lose money because there’s no way of restoring those colours once they’re gone.

There are a few documented cases of famous artists whose works began to deteriorate within their lifetime and buyers became very anxious about their investments.

Light is less of an issue with some mediums than others – oils tend to yellow and become more discoloured as time goes by, whereas watercolours degrade completely and turn white.

Lightfast pencils that are exposed to light will also fade but not as quickly as other types of lightfast art supplies.

Considering lightfastness when selling prints

When selling prints, and more specifically when creating your own prints to sell , artists must be aware that lightfastness is not the same among all media.

So it’s important to take lightfastness into account when selling your work or printing your art because buyers may want a print that lasts a century or more without any significant change in color.

So when selecting printer inks for inkjet or giclee printing, have a look at the lightfastness rating for the printer ink and if you can’t find a rating then use printer inks that are known to be ‘Archival’ as this means that it is rated to last at least 100 years.

What can a light-fading artist do about it?

The good news is you have options. Once you know how light affects different media, you can make better choices when creating your art and selling prints of your artwork.

In some cases, knowing which brands are lightfast might be enough to alleviate your worries – if one brand has been tested by

Supporting information

Winsor and Newton have a fantastic Masterclass video called ‘Testing Lightfastness‘ that helps explain how to test for lightfastness with a watercolor example and their own paints.

What is lightfastness and why does it matter – Wrap up!

While we have explored what Lightfastness is and why it is important for artists to know, we need to keep in mind that realistically, almost all paints will last quite a long time (many decades to hundreds of years) before they start fading.

The same with pencil pigments. Some inks, dyes and printer inks may fade much faster and even then they may not even fade much in our lifetime. So when choosing inks, dyes, paints and pencils, if you are not able to source a lightfastness rating then go for those that are classified as Archival, as this also means they are permanent.

Sources

“Ink & Pen lighttest – August 1 2015” by dgphelps is licensed under Creative Commons.

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