More on Pigments

My recent piece about the latest Winsor & Newton limited edition set raised a number of interesting questions. One of these was what was the point of buying them and wanting more, when you would be unable to buy replacements? Primarily due to the researches and knowledge of  a Facebook friend Zvonimir von Tosic we now possibly have some answers. I know that many artists are not that interested in pigments as such but it is a subject that fascinates me, even though I don't claim great technical expertise in either knowledge or approach. Without Zvonimirs input this piece would not have arisen so I am greatly indebted to him for discovering things are not as simple as they sometime appear.

Previously I have always consulted Handprint - and still do  - even though Bruce McEvoy ceased to update it several years ago.Much is still relevant but like all things nothing stands still. The pigment database- artiscreation.com/ColorCharts.html - is also a good source of information but quite technical.

Here is what Zvonimir has to say and I quote him in full:

"All right, I think I have an answer Peter. I have explored a little, so here is a brief summary. When producing certain types of pigment, say PV15 (this is one of the pigments used in a paint they call  `Smalt' in the latest W & N limited edition -PGW)., pigment manufacturers can obtain different `shades' of the colour, perhaps hundreds, depending on manufacturing process (errors, trials, beginning of run, end of run, stability of process etc).

However when analized spectographically, the wavelengths of all those batches are still within the acceptable range to be named PV15. But, our eyes being very sensitive to nuances, can tell the difference. In your tests of paints made `from seemingly same' pigments, but coming from different paint manufacturers like W & N, DS or Schminke, they may appear to differ. Therefore numbers`after' the number 15, and all manufacturers try to buy batches closer to their chosen shade.

What if all of them want to buy same, and at the same time, and there isn't enough ?

See chart (above). It shows variations on PV15 and PV14, which one pigment manufacturer is able to obtain( or has saved them in stock) in quantities ready to be utilised. They may keep batches piling up, or offer them to some paint manufacturers at a discount, who can make an interesting product out of them.

W & N reads industry newsletter, makes a phone call, takes a few tonnes of (PV)15583 for example, which looks bluer than what they used to buy for PV15, (in this case it may look like old Smalt). W & N purchases it, makes a limited run tube paint - perhaps because the manufacturer of that pigment does not or can not produce that specific variation in large quantities, and W & N knows what their users normally buy, with what types of colour shades users are happy with and can appreciate.

Colour recognition is a cultural phenomenon, and they play by the rules"

This has certainly widened my understanding of this subject. As said many may not be interested but to me it goes a long way to explaining why Permanent Rose from W & N (PV19) is such a favourite. And this applies to certain colours from other makers. I was aware that there are variations in pigments and have done posts where this has been highlighted,  for example PV19  where we have  red, rose and violet shades. 

One thing puzzles me slightly. Basically pigments are in two categories, natural and synthetic. With natural pigments like the earth colours there is considerable variation in shades, but I can understand this as they are mined and colours vary. Although it has been said these natural supplies are running out, and synthetics (PR101)  are replacing them,  there are still many available sources, perhaps not in such  large quantities. If you visit Provence you'll see this with shops selling nothing else and all sorts of colours visible in the rocks. In the Forest of Dean about thirty miles from where I live, between Bristol and Bath, are Clearwater Caves, a tourist attraction. Several earth colour shades are still mined there and sold in the shop, and on the internet I believe. 

With synthetics I would have thought they would be more consistent, being produced by a chemical process. I know the final result is determined to some extent by how the paint maker process the pigment and what additives they use. 

Here are five swatches, three of Ultramarine, two of PV14. The Graham Ultramarine Blue looks much darker than the other two but this may be my fault. Holbein and W & N look much closer. The above swatch is actually W & N French Ultramarine, and they also offer an Ultramarine `Green Shade'. With PV14 I've had problems with the Rowney version changing colour, a sludgy brown, and going hard in the tube. Another violet shade PV16, from Graham gave all sorts of problems and even the so-called final one - the third I received, using pigment from a different source according to Graham, has now also bitten the dust and has set like concrete!

As a final word Zvonimir has established from Graham that nowadays the same pigments are used in oils, acrylics and watercolours and the particle sizes are the same. This was apparently not so in the past. 

Quinacridone Gold - Pigment PO49

This colour, described by the Australian watercolour artist Robert Wade, in his 2002 book `Robert Wade's Watercolor Workshop Handbook', as the `best thing for years',  has had a rapid rise and - apparently - fall. Described by Handprint as a`mixed crystal form of PV19 Alpha and Beta' - I've no idea what that means - pigment production ceased in 2001 due to lack of demand from the automotive industry. This is again from Handprint who also say most paints with this pigment were discontinued in 2005. Initially there appeared to be four, two from Daniel Smith, the others from Winsor & Newton and Maimeri.

Winsor & Newton Quinacridone Gold became very popular in the UK. I can't speak for Daniel Smith which is still, as a brand,  only available in the USA ( recently extended to Canada).Note:20/10/12 Now available in the UK. It is possible (a little bird tells me) that  Daniel Smith, the largest range of watercolours in the World with over 200 paints, and highly acclaimed by American artists, may be available in the UK in the not too distant future.

Winsor and Newton reformulated `Quinacridone Gold' as a mixture now containing PR206, PV19 and PY150. All excellent pigments but don't expect the same results when mixing with others.

Maimeri continue to offer their version, called `Golden Lake', although the tube states it contains `quinacridone PV49.' I can find no trace of a `PV49' so assume it is a misprint that Maimeri have failed to correct - it has been like this since introduction. I contacted Bruce McEvoy about his comment that the paint was discontinued in 2005, which is what  Maimeri told him he says, and his reply was `the tube  may say that but....' .
An initial enquiry to Maimeri was promptly answered saying `Golden Lake' was still available and indeed they had supplied some to Jacksons, one of the largest UK art suppliers, in January. Following Bruce's comments I contacted Maimeri again and asked what was in the paint and why PV49? My e-mail was acknowledged but nothing further has been heard since. Hmmmmm!

Is that the end of it? On checking through lists of paints from several leading makers I came across this from Sennelier, the French manufacturer. According to their current pigment information PO49 is listed in five paints, all mixtures. Quinacridone Gold (with PG7), Mars Yellow (with PBr7), French Ochre (with PG23,PY3), Yellow Lake (with PY153), and Chinese Orange (with PR209)! No shortage of PO49 there it seems but no pure pigment paint either. I believe, until recently at least, Daniel Smith was still offering Quinacridone Gold in it's huge range. However since writing this I note that the new Great Art catalogue http://www.greatart.co.uk/ has a watercolour chart for Sennelier with one difference. Quinacridone Gold, as a name, has vanished and under the same number 445 is something called `Brown Pink'.Note: 20/10/12. Sennelier reformulated their range in 2012.

I only have experience with the W & N and Maimeri versions. Winsor & Newton Quinacridone Gold  was lighter and handled better than `Golden Lake', which I have not been impressed with. I like Maimeri paints, which are excellent value, but this colour is darker and grittier than the original Winsor & Newton paint. What actually is in the tube? The silence from Maimeri makes me wonder.Note:20/10/12. Information from Maimeri to Handprint said they had replaced PO49 with PY43 `a similar pigment'.

As a footnote the closely allied Quinacridone Orange PO48 is also heading for the exit due to `lack of demand from the automotive industry'. This is another lovely pigment and the Graham version, Quinacridone Rust, is a gorgeous colour.  The new Da Vinci (USA) range also includes paints listing this pigment. Both Graham and Da Vinci are only available from T.E Lawrence of Hove in the UK http://www.lawrence.co.uk/, while Maimeri from Jacksons  http://www.jacksonsart.co.uk/ and Turnham http://www.artistmaterial.co.uk/ , possibly a few others. Jacksons also sell Sennelier.

Value or Tone

Value describes how light or dark a colour is. This is relatively easy on a grey scale, basically starting with white and finishing with black. Between six and ten steps seems to be the norm. I have used six. However how and  what value do you ascribe to different colours? The following is a value chart I made up using as guidance the `artist's value wheel' from the  Handprint site http://www.handprint.com/HP/WCL/color11.html#wheel .

Apart from black the darkest value is Indanthrone Blue (PB60). Windsor & Newton, Daler Rowney and Rembrandt call this `Indanthrene Blue', Maimeri `Faience Blue, Scminke have two paints using PB60. `Delft Blue' and `Dark Blue Indigo', Holbein `Royal Blue' and Graham `Anthraquinone Blue'! Neither `White Knights nor Shin Han list this pigment, which is at the expensive end. Confusing isn't it which is one reason why manufacturers names have to be taken with a pinch of salt. Most manufacturers now put pigment information on tube paint, not usually pans, but often so small as to need a magnifying glass to read it.  I have taken  Bruce MacEvoys spelling as the correct one but will investigate further. On my chart while you can't read the letters (try clicking and enlarging ) indicating what each paint is the colours are clear enough. I wouldn't claim it to be 100% accurate but I think reasonably so.

Amongst the very darkest values is Diozazine Violet ( PV23) called  Windsor Violet and Rowney Permanent Mauve and so on. Check the pigment information on the tube or hunt it down from the various manufacturers websites. One excellent commercial source is DIck Blick Art Supplies http://www.dickblick.com/  Dick Blick has a huge number of watercolour paints and if you click on the individual paints it will lead to pigment information. This has to be done with every single paint separately and needs a little patience.

Other very dark colours are Prussian (PB27) and Ultramarine blue (PB29), Burnt Umber (PBr7) and Quinacridone Violet (PV19). There are others so if you wish to pursue this any further, and I can understand many not wanting to do so, then get the Handprint value wheel. It can be downloaded and printed.

At the other end of the scale, apart from white, Cadmium Lemon (PY35) is the lightest value with all yellow and yellow shades coming into the lighter half of the chart and the reds, blues and greens in the darker one. This is a generalisation as there are variations so get the chart for specific details.