#lightfastness

Whether it’s old fashioned gouache paints or modern markers, designer’s art materials WILL fade and change or even destroy your artworks, no matter how strong or bright their colors may look at first.

An example: This is the cover of the “New Yorker” magazine dated March 12, 1938, made from a color photograph of a gouache painting by illustrator Garrett Price.

(The pale greyish splotches on the 1938 magazine cover are age spots on the paper and not part of the original artwork.

This is called "foxing" in the antiquarian book collecting world.)

This is a photo of Garrett Price's original gouache painting — in the condition it was in at a 1999 auction.

Haunting!

What happened? Over the years daylight or maybe just even time passing faded the colors of the gouache paint Price used … Because designers’ gouache paint is not a permanent artist’s material. It’s not MADE to last.

When you put the two images side by side it’s even more stark. The central woman's deep rose pink dress has faded to a barely-there ghost-beige.

The rich green cornucopia looks completely different.

Most of the blue ribbons and pink flowers are completely gone, leaving the purple parts as faint mauve ghosts hanging in the air.

Even the nice black outlines are gone. Black should be a permanent color!

The pretzels have faded to a pale doughy mass.

Gouache paints are made to be bright for ephemeral advertising art and posters. They really are not suitable for any art that is meant to last. Any artist interested in the longevity of their hard work should use archival materials such as artist’s watercolors or professional acrylic paints instead of designers' gouache or markers, no matter how attractive the colors.

And don't think that because this was from 1938 things have changed that much. They were still selling designer gouache with fugitive pigments when I was an art student and art supply stores are still selling them now. And those markers are modern.

Okay, okay, you're about to be subjected to one of my favourite topics, so if you have no interest in traditional art and why some stuff fades away (quite literally) then move along.

But if you're like me, and you want to know more about pigments vs dyes and why your pink thing has over time become a white thing, keep reading…

So, my interest, aka my dive into the rabbit hole that is lightfastness, started way back when I made a friend a bright pink thing (cheap student grade acrylic paint on canvas board) , they hung it up in their window, and it slowly turned into a white thing.

Gasp! Shock! Horror!

No really, I was slightly traumatized, simply because I was about to start selling my artwork and if it was going to fade away in the space of a year odd, then I was going to have a big problem. I mean, you can't sell art and then tell people they must keep it in a dark place and only observe it under moonlight. Well okay you probably could if you marketed it right, but I'm terrible at marketing and the idea of someone coming back to complain about the art disappearing gives me anxiety.

So I went on a hunt to find out WHY.

So let's talk about pigments vs dyes and what fugitive pigments are, and why artist grade is so much more expensive than student grade.

What's the difference between pigments and dyes?

Think of paint made from pigments as a suspension, finely ground up particles are suspended in a medium, much like mixing sand into water. If you let a sandy water mix sit for long enough the sand particles will sink to the bottom and separate from the water. Pigment based paint sits on the surface of your canvas or paper (yep even watercolours, the paper gets wet, but when it dries the pigments are sitting on the surface, they haven't sunk in and bonded with the paper). Pigment based paint is more inclined to be opaque.

Paint made from dyes are a solution, very very finely ground particles are dissolved into a medium and change their chemical makeup, you can let them sit as long as you like and they won't separate. Dyes sink into the surface of the paper or canvas. Dyes are naturally transparent. Dyes are used for fabric precisely because they sink into the surface and bond with it.

So, those fugitive pigments huh?

I'll start with the kicker, dyes, by their very nature, are fugitive. Let me explain that a bit more - dyes are a solution, they have chemically bonded with the medium and because of this chemical change they are much more vulnerable to UV light, to the point they can completely disappear. Alcohol markers are a prime example of this. This is also why clothing fades over time.

Any fluorescent colour is fugitive. Don't ask me why, they just are.

So what about pigments? Well, if you mix them with oil, pretty much all the pigments will manage to stick around, oil creates a protective coating that shields the pigments from UV light.

Not so with other mediums though, so some pigments will fade over time. As paint companies have become aware of this, they have tried to find alternative pigments that are light-fast and you will find a light-fast rating on good brands of paint.

The white factor.

White tends to be opaque and is very light-fast, it's usually PW6 pigment for titanium white and PW5 for zinc white, which is also known as the mixing white and is supposedly less opaque - personally I can't tell the difference.

So, white, all good, gonna use white which is light-fast and this tube of red which is also listed as light-fast and make pink, no worries right? Wrong.

Mixing white into other pigments can make them less light-fast. Why???? I hear you scream.

It's to do with (someone correct me if I'm wrong but this is my understanding) the fact white reflects light, so as soon as you mix another pigment into white, not only is the concentration of the pigment reduced, it's also at the mercy of all that extra light. Some pigments are naturally very light-fast anyway and being mixed with white won't be much of an issue.

Avoiding the known fugitive pigments is a good start to ensuring your artwork is going to stick around for the long haul, of course painting in oils is more of a guarantee but not everyone can be bothered with the mess.

So, artist grade vs student grade?

In general artist grade paint will have a light-fast rating, list the pigments used AND most importantly they will contain much more pigment and better quality pigments than cheaper paints. More pigment means stronger more vibrant colours, you need less paint to cover a surface, there are no fillers like chalk to make the paint opaque and the quality of the pigments is higher. Basically when you buy artist grade paint you are paying for the pigments used, you're more likely to find single pigment paints and the pigments are more likely to be light-fast.

Of course oil paint can pretty much ignore this, buy whatever works for you, it's not going to matter much.

What about student grade? Well, student grade from a reputable brand may still give you a list of pigments and a light-fast rating, you can feel pretty assured that the paint will perform as required, but the pigments will be cheaper and less concentrated. If, like me, you have found yourself utterly annoyed you can't get a vibrant enough look from your student grade paint no matter how much you apply, then this is why, it simply doesn't have the same amount of pigment as the artist grade in the same brand does. While the artist grade is more expensive, my personal findings with watercolours are that I use much less of it because it is more pigmented, so it works out more cost effective in the long run.

Student grade will often substitute an original pigment for a 'hue', like 'cadmium red hue' which is a replication of the colour and doesn't actually contain the cadmium red pigment. So you get a lower cost pigment in a lesser concentration.

Student grade paint generally won't be as concerned with using light-fast pigments, so you're more likely to find less permanent pigments and also pigment mixtures rather than pure single pigment paints.

What's the difference between single pigment and mixed pigment? Glad you asked. It's the mud factor, we've all mixed paints together and come out with a sludgy grey muddy colour right? Mixed pigment paints when they contain multiple pigments are more likely to give you dull muddy colour when you mix them with other paints, simply because mixing complimentary colours together will give you a neutral grey. (Stares hatefully at reeves watercolours, my first experience with mud production and chalkiness)

Single pigment paints are easier to mix vibrant colours with.

What about student grade, or ungraded paint from non recognized brands? Well, generally they make up their own names for the colours, they give you no pigment or light-fast rating (though many claim to be light-fast, they show no actual ratings and can't be trusted) and they can often contain dyes as well as fugitive pigments, because they are cheaper to use. They will contain a lot of fillers and less pigments, and can be harder and more frustrating to use. It's not always the case of course, but in general you get what you pay for.

Finally, designer mediums vs art mediums.

Or - was never intended to last vs meant to be hung on a wall.

Some currently popular and commonly used mediums were never intended for preservation. They were created for design, be it architecture, fashion design, magazine illustrations or other things that were made to be photographed and then reproduced in print.

Prime examples of this are alcohol markers and gouache. They were never ever intended to be light-fast, they were made for quick execution and reproduction, the original was often just thrown out.

Gouache, because it dries fast and is matte makes it perfect for both quick turnaround illustrations and reproduction. The matte surface makes photography easy without any worries about reflected light messing up the image. It was used extensively in the magazine and printed periodical industry.

Alcohol markers were more aimed at the design industry.

Gouache, by it's very design tends to still be very inclined to use fugitive pigments, Windsor & Newton do have some with high light-fast ratings, but you have to read the labels carefully and if you use the paint as a wash it's still going to say goodbye faster than it should (it's the white factor again, this time it's the white of the paper).

Alcohol markers, as I've said before, are dye based, and are highly fugitive. (Do I get mad when people sell original art done in alcohol markers, yeah, a little bit, I feel bad for the person buying it who presumably wants to put it on the wall and it IS going to fade away. I don't see anything wrong with selling the artwork, markers have their own charm and the effects are quite unique, but you should at least warn people that it's fugitive)

Most calligraphy inks designed to go inside pens are dye based and will fade. (Gel writing pens too, even in closed books that will fade drastically, ask me how I know!) (Pigment based ones tend to clog so are reserved for dip pens and brushes, and are usually mixed with shellac to make them waterproof. )

Don't be put off using these mediums, they are great fun to play around with, just be aware that they are not designed to be exposed to light for long periods of time are best for reproduction as prints.

Can you enhance the lightfastness of a painting?

Yep, put it behind glass (perspex is even better?). I think it's possible to find UV resistant varnish too, but don't quote me on that, I haven't seen any myself. I don't think this is a reliable method for dye based art though sadly, while watercolours behind glass will last longer, some dyes can fade away even without light on them (see the gel pen experience)

Can you do your own lightfastness test on your mediums?

Sure can, as long as you have a control swatches kept in a dark place, you can put swatches in direct sunlight and compare them to the ones you kept in the dark to see how much they have faded and how long it took. Some will show no signs of fade even after a year of direct sunlight, some might disappear completely, it will depend on the pigments.