Lightfast: meaning and importance
Disclaimer: I’m going to use pencils as a reference, but lightfastness applies to all mediums, such as pencils, pens, pastels, inks, paints, etc, and the scales that I will be mentioning are used for most mediums as well.
What exactly does lightfastness mean?
Lightfastness proper definition is the quality of being unaffected by light.
When talking about art, it’s a term that express how the pigment of the art materials you are using interacts with the light itself. It is also a measurement of a pigment’s ability to resist fading or discolouration under normal circumstances. This can be any source of light, like sunlight or artificial ultraviolet light.
Colour fading is something that naturally happens to pigments and lightfastness determines how long it is going to take for that colour on your piece of art to fade. If you have used poor lightfast materials, then a change of colour might be noticeable in 4 months to a year when exposed to direct light. But good lightfast materials will allow for that pigment to stay the same for more than 50 – 100 years.
How do I find out if the material I want to use is lightfast or not?
Products that are not lightfast will have little to no information about the material lightfastness. A great example of this are materials designed for children.
Professional art materials that are lightfast will almost always have that information printed on the product itself. And if you buy a set, most of the time it will come with a colour and lightfastness chart. If it doesn't, then you will be able to find that information through the brand’s website.
Colour and lightfast charts for Caran d’Ache luminance, Derwent Lightfast and PanPastels. All of this came with a set.
Lightfast scales
Different companies use different scales to measure how lightfast their pencils are. There are two main scales to measure lightfastness. The blue wool scale and the ASTM scale.
Blue wool scale
It operates from numbers 1-8. 1 being extremely poor lightfastness and 8 being the absolute maximum lightfastness possible. In this scale, anything that is a 6 or above is considered acceptable for professional artists.
Examples:
ASTM D6901 scale
It uses a roman numeral system going from I to VI. In this case I is the highest form of lightfast possible and VI is extremely poor lightfastness. It is the opposite of the blue wool scale.
Examples:
Star rating system
Some manufacturers use a star scaling system, for example Caran d’ache Pablo’s uses a star system with 1 star being good lightfastness and 3 stars representing excellent lightfastness. Same with faber castell polychromos.
Examples:
Faber-Castell polychromos and Caran d'ache Pablo's might be a bit confusing because they both use the Blue Wool scale. But when it comes to showing that information on the pencil, you can find a star rating system at the back of the pencil
So whenever you're planning on purchasing either Faber Castell polychromos or Caran d'ache Pablo make sure to check of these stars that are at the very back in order to know which level of lightfastness that pencil has.
Either way, I always recommend reading what scale is being used for each art material to avoid confusion.
Why is it so important for artist?
Most artists who sell their original artwork want to make sure that they are giving their customers a product with the highest quality possible. Using pencils that are lightfast, ensures that people who buy that artwork will not experience any fading or colour changes when being exposed to light. We want to make sure that, no matter where the customer hangs that artwork, nothing will happen to it.
It is true however, that because this art materials have the special quality of not fading under light, they are more expensive.
Should you worry about the lightfastness of your art materials?
The answer is: it depends.
If you are a professional artist, then the lightfastness of the materials you use is something that you should definitely worry about. Using poor quality materials will increase the chances of the colour of your art pieces fading rapidly, meaning not very happy customers. No one wants to have customers calling after a few months or a year complaining that the art piece they have purchased has had a coloured change.
However, this will change if you are just producing artwork to sell prints, as you will be able to store that piece away from light and just focused on having lightfast inks for the print.
Now, if you are a beginner artist who is not yet selling their work or you are just a hobby artist, then lightfastness is not something to worry about. Materials with high levels of lightfast are usually more expensive and I understand that, that is something many hobby artists will not be able to afford and even if they can afford it sometimes they might not want to spend that much money on art products.
The truth is that while having more professional art materials is definitely worth it, it can wait until you decide to start your own art business or are ready to take your skills to the next level.
Resources:
🎨 Lightfast charts links:
