Watercolour Myths (Part 1) – Watercolours have poor lightfastness

Working as a primarily watercolour artist, I have heard some frequently repeated myths from customers as well as other artists, which I would like to dispell.

The first myth I hear very frequently is “Doesn’t watercolour fade?”.

The short answer is no, my watercolour paintings will not fade.  In fact, most watercolour paintings you buy from professional artists should be just as durable as other media, especially if framed behind conservation glass.

Paint Composition

Watercolour, like most other artistic paint media such as acrylic paint, oil paint, etc, is composed of pigments held together with a binder. For oil paint, this is a drying oil such as linseed oil or walnut oil, for acrylic this is an acrylic emulsion (a synthetic plastic product that hardens in contact with air).

The primary binder in watercolour is gum arabic, a resin made from acacia sap, and sometimes honey.  Gum arabic and honey are no more prone to discolouration or other long term effects than other binders.  In fact, oil-based binders have a tendency to yellow over time, as do acrylics (which as a newer media, have not yet stood the test of time).

Pigments are naturally occuring and synthetic colourful chemical compounds, which paint manufacturers mix with binders to create paint.  In modern days, we are spoiled with a wide variety of stable pigments, thanks to global shipping and modern chemistry.   With a little bit of care, artists in all media can use a palette of extremely lightfast, durable colours which will not fade or change colour under any circumstances.

In the past, artists had very limited choices in some parts of the colour spectrum.  For instance, before modern lightfast synthetic rose colours such as Quinacridone Rose (PV19) became available, artists had no choice but to use less reliable pigments such as Alizarin Crimson (PR83 ) or extremely fugitive genuine carmine (NR4).

Lightfastness is a problem across all media, not just watercolour

Portrait of Charles Churchill, by Joshua Reynolds. National Gallery of Canada

Poor lightfastness is by no means unique to watercolours.  Oil or acrylic paintings made using carmine or other fugitive pigments will also eventually fade.  To the left is a portrait of Charles Churchill.  It now looks ghostly, but when it was originally painted, the subject’s cheeks were likely rosy, and the coat a deep red, through the extensive use of carmine and other fugitive pigments, long since gone.

However, in oil paint, the thicker paint film provides a small amount of UV protection, so an oil painting using fugitive paints may last a little longer than an unprotected watercolour framed behind clear glass.

Modern artist-grade paints are generally not made with highly fugitive pigments such as carmine anymore.  However, some specialty paints (such as neon paints and some common brands of liquid watercolours) as well as cheap scholastic grade paints, are made with fugitive dyes instead of traditional pigments (again, this is equally true in non-watercolour media).  In addition, some pigments with limited lightfastness are still used in artist paint lines (for example, alizarin crimson is still a common pigment which many artists use.   While more durable than carmine, alizarin still has a significantly lower lightfastness than similar quinacridone-based pigments)

How much do you really care about lightfastness?

Dining room Art
Cote-des-Neiges Oil Landscape by Carly Leyburne

Some artists prefer to use impermanent materials for immediate impact, rather than creating artwork that will last centuries.  Most popular mixed-media, collages including newspaper clipping or plant matter, resin etc are prime examples of this.  Similarly, some painters use neon paints, which are virtually all fugitive.

There’s nothing wrong with buying and displaying art for your enjoyment that won’t last forever.  For example, I purchased the beautiful oil painting shown on the right (by my studio mate Carly Leyburne) as a statement piece for my dining room.  The hot pink trees are painted with an oil paint that includes a rhodamine dye, which will eventually fade.  I am not concerned.  It looks fantastic right now.  We’ll cross the fading bridge when we get to it.  I may be old and senile by then anyway 😉

If you are unsure of the pigments used in your watercolour paintings, and would like to ensure they stay looking bright for years to come, framing your art behind conservation glass (which offers significant UV protection) and not hanging it in direct sunlight can dramatically slow any fading in both watercolour and other media.

How to ensure you are creating lightfast art

I am happy to buy any art that catches my eye, with little concern for archival qualities.  However, as a seller, I do feel compelled to stay one step ahead, and ensure that my artwork will continue to look bright and fresh, regardless of how my customers choose to frame or display it.

If you are an artist looking to produce artwork that will last for centuries, you can ensure the durability of your pieces by eliminating pigments from your palette which do not have an “excellent” or “very good” lightfastness rating.

The most durable pigments should last centuries without discernable change, given proper framing and protection.  Below, I’ve listed a few common paints to watch out for, as well as alternatives.  This list is by no means exhaustive – do your homework and research the specific paints that you use if lightfastness is a concern for you

“Opera Rose” and other paints containing rhodamine dye (BV10):  Probably the least lightfast paint in most modern paint lines, “Opera Rose” is a  hot pink, popular with botanical artists looking for the brightest colour.  Usually formulated with PR122 (Quinacridone Magenta) and rhodamine B dye.  The rhodamine is highly fugitive, if exposed to sunlight, this will lose brightness, fading back to the (still fairly bright, but not neon) PR122.  A safer alternative is to just stick with Purple Magenta (PR122) to begin with.

Alizarin Crimson (PR83):  An early synthetic and once the most stable “cool” red,  Alizarin Crimson is a relatively dull, deep rosy red.  It is now considered relatively fugitive compared to the many available permanent red pigments. Many modern paint manufacturers still offer Alizarin Crimson, and it is favoured by portrait artists and traditionalists over the brighter, modern quinacridone rose (PV19) for mixing skintones and rosy lips because it is slightly muted. However, it isn’t very permanent.  Many brands offer a “permanent alizarin crimson” formulated with quinacridone red (PR206) or redder shades of quinacridone violet (PV19).  I use Quinacridone Rose (PV19)  or Purple Magenta (PR122) for most mixing, and Perylene

Hansa Yellow Lemon (PY3 and PY1):  The moderately lightfast Hansa Yellow Lemon (PY3) is one of the most common lemon yellow pigments available.  It is much more transparent and highly tinting than other pigments in this range.  PY3’s close cousin PY1 (also a Hansa Yellow Lemon) is even less lightfast, yet is still available in some paint lines.  An increasing number of paint brands have started offering Lemon Yellow paints made with PY175 , an azo lemon yellow with a “very good”lightfastness rating.

Dioxazine Violet(PV23): Present in nearly every watercolour line, dioxazine violet varies in lightfastness depending on manufacturing. It is a deep, saturated, transparent and non-granulating bright cool violet colour, in a portion of the colour wheel with relatively few pigment alternatives.  It is also a relatively inexpensive pigment, whcih no doubt contributes to it’s enduring popularity.  There is no single pigment replacement for dioxazine violet, however, hues can easily be mixed from a warmer violet shade such as quinacridone purple (PV55) and a splash of a blue.

Rose Madder Genuine:  Most brands have discontinued this pigment, but Winsor Newton have made it their flagship colour.  The Winsor Newton paint is scented with bergamot – originally to please Queen Victoria.  It is a slightly muted, liftable colour similar in hue to Quinacridone Rose (PV19) but lighter and more muted.  Just use quinacridones. For a muted pink with some granulation, try Potter’s Pink (PR233)

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Clumping of non-granulating watercolours – A clue from indian ink!

Apparently I just can’t let this subject go.  I am becoming the crazy water hardness and watercolour clumping  lady.    Recently I was reminded of this problem/puzzle while planning for participating in Inktober.

A few months ago, I saw a really cool demonstration by Stephanie Pui-Mun Law on Youtube.

Artwork by Stephanie Pui-Mun Law demonstrating textural ink techniques

In this video she demonstrates how she creates dramatic, organic-looking textural effects using Winsor & Newton Indian Ink diluted in water.  When mixed with tap water the ink clumps up, and deposits in a granulating texture on the paper.

Being a water-resistant ink, this can then be worked over with transparent watercolour without destroying the granulation pattern.  I thought this might be useful for some spotting effects I commonly see on dry grasses and

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Drawing Ink by Winsor & Newton (Image property of Winsor & Newton)

seed pods in winter, and stashed the tip away for possible future use.

I’ve been thinking about what to do for Inktober. I would like to try in

king with liquid ink and a brush for some of my pieces.  While thinking about what to do with liquid ink,  I saw some other recommendations to thin it out for grey washes.  I was reminded of the Stephanie Law video, and decided to look up Winsor & Newton ink specifically.

On the Jackson’s art listing for Winsor & Newton’s waterproof ink, I found something very interesting:

 

Jackson's India Ink Screenshop
Jackson’s Art Page for Winsor Newton’s India Ink

See that yellow highlighted paragraph.  Here’s what it says:

The colours can be easily diluted with water to reduce the strength of the colour or to increase it’s transparency. Distilled water must be used as tap water causes the dye to separate from the binder.

Yep, that’s right.  Winsor & Newton drawing inks are watersoluble, but only in distilled water.  Even small amounts of dissolved minerals in tap water cause the ink particles to clump and curdle out of solution, causing the textural effects that Stephanie Pui-Mun Law uses to such great effect in her pieces.  This behaviour is similar to what I experienced in M. Graham watercolor paints.

I wonder whether there is a similarity between the binder(s) used in the Winsor & Newton inks and the M. Graham paints.  Very intriguing.

 

 

 

Clumping of Non-Granulating Watercolour Paints, Part 2 – It’s not me, it’s you, M. Graham

Several weeks ago, I wrote what turned out to become my most popular blog post yet.  In it, I explored the effect of water hardness and dissolved mineral content in water on watercolour paints on the palette and on paper.

In particular, I was trying to find an explanation for some weird curdling/clumping behaviour I was observing in quinacridone paints from M. Graham.  When I experimented by switching my brushwater from Kitchener-Waterloo tap water (some of the hardest in North America, containing extremely high levels of dissolved calcium and magnesium) to store-bought distilled water, I observed a marked reduction, but not a complete elimination of curdling effects

Comparison
Original Experiment:  Tap water vs. Distilled, used pans/washed in tap water

At the time of my original post, I attributed the remaining curdling/clumping in the distilled water sheet to mineral buildup in my pans, brushes and palette from previously using tap water.  I theorized that if I switched to distilled water for my painting, over time, this would improve.  I could also reduce the effect of mineral residue on my palettes by wiping them off after washing, and rinsing my brushes in distilled water.  At the time, I was cautiously optimistic that I would be able to all but eliminate this problem with changes to my painting routine.

Over the past few weeks, I have been dilligent about using only distilled water. I no longer think this is a realistic solution, and I now have serious  doubts that this is the only reason for my M. Graham paints curdling.  A few things have changed my mind:

  1.  Despite my dilligence in using only distilled water, all the affected M. Graham paints continue to curdle.  In the case of the quinacridone rose, this effect has reduced enough that it is now no longer as bothersome.  However, the neutral tint still sometimes separates, and the Quinacridone Rust(PO48) still clumps dramatically.  In this case, I have gone as far as to fill a fresh pan, tried using paint straight from the tube, even washed my palettes with distilled water, to no avail.  No matter what I do, if I water this paint down, or try to mix it with another colour, it still clumps. If this is indeed simply a reaction with some minerals, it is reacting with extremely low mineral content, lower than most tap, filtered or bottled water most artists use.
  2. While I am willing, grudgingly, to buy distilled water and haul it to the studio for studio use, I also enjoy carrying around palettes for urban sketching, field studies, etc.  In these cases I will use whatever water is handy – filled from a drinking fountain, lake water, bottled mineral water, etc.  I now find myself concerned not only about whether my paints will unexpectedly clump with the water of the day, but whether I will be messing up my pans by leaving mineral residue in them.  This is ridiculous and unacceptable
  3. In a bizarre mix of frustration and optimism, a couple weeks ago I purchased both a replacement PO48 (Quinacridone Burnt Orange, by Da Vinci) and another supposedly non-granulating M. Graham paint (PG36- Phthalo Green YS).  The Da Vinci paint performs beautifully, a very similar colour to the M. Graham, but not a hint of clumping no matter what water I throw at it – whatever the issue is, it’s clearly not merely pigment related.  The new phthalo from M. Graham, on the other hand, does some bizarre stuff.  It clumps dramatically on the palette, although how much varies day to day, but then the clumping relaxes and all but dissappears as the paint dries on the paper.
  4. Just as I was beginning to really think I was going insane, consistently seeing paint behaviour that nobody else has reported, an amazing Youtuber I follow,  Sadiesavestheday, commented on the same thing in one of her videos (skip to 14:30)

I’m running out of ideas of what could be causing this.  It has occured to me that it could be the honey crystallizing inside the paint due to living in a climate with dramatic temperature swings, but that would also fall under the unnacceptable paint behaviour category.

So where does this leave me?  I’m actually really upset, because, as I’ve raved before, I love the rewettability and saturation of M. Graham paints.  I love their pigment choices and focus on single pigments. Their PY150 Nickel Azo Yellow is hands down my favourite (read: only) yellow. and I love a bunch of their other pigments too.  However,  at this point 4 of the 10 or so M. Graham paints I own display some level of frustrating clumping.  While it is possible to mitigate and work around this in most cases, none of my paints from any other brand have this issue, so I am reaching the conclusion that it will simply be easier to just buy from other brands in the future.

So I guess this is my breakup letter to M. Graham, at least for now.  M. Graham, it’s not me, it’s you.  I just can’t handle your high maintenance needs and mood swings anymore.  I’ll be moving on to more reliable, easygoing paints.

I will reach out to the manufacturer at some point in the near future.   I hear they are very receptive to feedback. I hope that they will be able to track down the root of the issue and fix it, so I can once again enjoy these pretty colours.

 

Effects of water hardness on watercolour paints

For the past couple of years,  my tap water has been curdling my paints.

It all started with a tube of Quinacridone Rust (PO48)  from M. Graham.   I was attracted to this paint partially because the pigment is listed as non-granulating,  and I fell in love with the colour, but ever since I got it, the paint has had a tendency to clump and curdle when mixed with water in the palette or dropped into a wash, resulting in an incredibly pronounced granulation pattern.  This pattern becomes even more pronounced when Quin. Rust is mixed with another dark valued, non granulating paint such as a phthalo.

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Colour mixing experiments with Quin Rust (PO48) and Phthalo Turquoise (PB16)

I searched the internet extensively, and could find no other reports of quinacridone rust granulating like this.  For months I was actually convinced I had received a dud tube, but avoided investigating further, because I really adore the colour and transparency of the tube I own.  Instead, I simply developed strategies for mitigating the crazy clumping and curdling.

Then, a few months ago, I purchased two more quinacridone paints by M. Graham – Quinacridone Rose (PV19)  and Neutral Tint (PV19 + PG7).  Again, all of the pigments are listed as non-granulating, but both of these paints showed the same clumping/curdling behaviour (albeit to a lesser extent).

Now, one dud tube would be easy to explain, but 3 dud tubes purchased at different times would reflect very poorly on the manufacturer.  And yet, still I could find no reports of similar experiences online.  I felt like I was going crazy.

IMG_20170425_152344
PV19 Quinacridone Rose (M. Graham) on palette with KW water

Finally, I reached out to other botanical artists and asked around.  Someone suggested I should paint with distilled water, as acidity and mineral in tap water can react with some paints.  Suddenly it clicked.   I live in Kitchener-Waterloo, known to have the hardest water in all of North America.

Water hardness refers to the amount of dissolved calcium and magnesium in the water.  Water tends to be harder when drawn as groundwater rather than from lakes or streams.  Water hardness leads to limescale deposits in pipes and fixtures, and premature degradation of water heaters in pipes.  In my area, most households (including my own) have a home water softener, which functions by replacing the dissolved calcium/magnesium with sodium.  We shower and do our dishes with saltwater, which is not drinkable, and have a hard-water tap direct from the city for drinking water. At my art studio, a few blocks away, we do not have a softener.  Thus, my paintings in the past few years have all been done with limewater, and perhaps occasionally saltwater.

In order to test the effects of the tap water on my paints, I purchased a large jug of distilled water at the grocery store, and painted out samples wet-in-wet and wet-on-dry on identical paper using hard water vs. distilled water.

Comparison.png

The difference between the two samples was dramatic.  However, there was still a little bit of texture visible in some of the paintouts even when using distilled brushwater.  I attribute this to mineral build-ups in the pans themselves, as well on the brush and the plates I use as palettes, which of course get washed in tap water.  I even tried a sample using fresh tube paints, which was even cleaner, but still contained a little bit of granulation.

So, from now on, I will be painting using distilled water.  My paints are much posher than me, and will get fancier drinking water than I do.  Eventually, I will have a reverse osmosis system installed for the drinking water line at home, although likely not at the studio, which is a rental shared with other artists.  I will however be able to fill up a bottle at home and take it to the studio.  However, I can’t imagine going through the trouble of only washing my palettes and brushes with distilled/RO water, so some hardness effects will still be seen.

I am somewhat torn about manufacturers.  I love the brightness and saturation of M. Graham paints, but they seem to be much more prone to this kind of curdling. Since running this test, I did look through my mixing charts and found a few other paints where some minor unexpected texture, but nothing remotely close to what is seen in these three paints.

My quinacridone pigments from other manufacturers do not show nearly as much clumping.  My PV19 Permanent Rose from Winsor Newton is unfortunately not as bold and red as the M. Graham version, but it shows only the faintest amount of texture even in hard water.  My PR122 Purple Magenta and PV55 Quinacridone Purple from Schmincke and PO49 Quin. Gold from Daniel Smith are also quinacridone pigments, but paint out completely smooth.  Given that in most cases I prefer smooth, non-granulating paint, and that my paint will no doubt continue to come into contact with some dissolved calcium and magnesium, would I be better served switching to different manufacturers for quinacridones (and any other paint that may be similarly affected)?

Does anyone know what the chemical reaction occuring might be in these cases?