Problem colours or pigments?

A while ago I related my problems  with the Graham Mineral Violet (PV16). The first 15 ml tube was half empty and a complaint to Lawrence, the sole UK source, was promptly dealt with and a new tube despatched. I didn't attempt to paint with the colour for several months and when I did found the tube had solidified into a horrible muddy brown. Again I contacted Lawrence www.lawrence.co.uk who were very good, explaining that Graham said this was  due to a faulty batch of pigment, and  had subsequently changed their supplier. A third tube arrived which I was assured was the real thing. Although I don't use this colour much I have a secondary palette and  sqeezed colour into one of the wells. After a while I noticed it was changing colour - the muddy brown again! By skimming quite a lot of paint off the top I returned to the `true' colour - at least I think it is. The only way round this seems to be to  squeeze out a small amount of paint prior to using it. However my conclusion from all this is AVOID.  I stress this is my experience with only one make and others may be fine, but this isn't a popular pigment and rarely features in artist palettes. I have many other Graham paints and am generally very pleased with them so this isn't a condemnation of Graham. Charles Reid uses Holbein Mineral Violet BUT this is PV15 not 16, in other words Ultramarine Violet.

The Cobalt Violet is 4th bottom left but look at the paint 3rd bottom left!

What does Handprint  www.handprint.com/HP/WCL/waterfs.html the indispensable reference say? The initial surprise is that it is rated a `Top Forty' pigment by  Bruce McEvoy. He continues:

 `Manganese Violet PV16 is a very lightfast, semitransparent, lightly staining, dark valued, moderately dull red-violet pigment, available from 4 pigment manufacturers worldwide'.

 He also says the PV16 pigment is very consistent across paint manufacturers. Six versions  are listed variously called Manganese Violet, Permanent Mauve (W & N) and Mineral Violet. Old Holland call it Manganese Violet-Blue and this discoloured to a brownish cast in his sample. Shades of my experience with Graham.

The second problem colour/pigment is the Rowney PV14 Cobalt Magenta. Like all cobalts it is very expensive, although the Rowney version considerably less so than others. It may be that I'm exaggerating the problem but certainly over a period the same sort of horrible muddy discolouring took place and I had to discard quite a lump of paint because of it. What to do? I sqeezed out a small amount  as I did with Mineral Violet and so far - about a week to ten days - the colour remains the same. I quite like the colour and it granulates beautifully if a little weak.

What does Handprint say? Another Top Forty pigment! He goes on to say:

 `Cobalt Violet PV14 (often labelled "cobalt violet deep") is a very lightfast,semi-transparent, nonstaining, moderately dark valued, moderately dull violet to red-violet pigment, available from 4 pigment manufacturers worldwide'. 

Again this is not the most popular of pigments although a number of manufacturers list it. The paints on offer show a noticeable variation (Handprint) and colour varies from light to dark valued. Some disparage it as `weak and gummy' but , again according to Handprint, the `genuine, high quality,cobalt violet is a spectacular paint on broad wash applications'.

Interestingly I spotted a pan of Cobalt Violet in Charles Reid's palette at my last Crantock course in 2011. Charles has taken to using some pans although he prefers tube colours. This is due to the problems associated with moist watercolours when travelling. He never mentioned this colour when discussing his palette but I notice that on his latest DVD, `Figurative Watercolours', the figure of the man has some on his clothing. Almost certainly this is the Winsor & Newton version.

What to do? If you like this colour, and I do, what make to buy. I have just this minute looked at my palette again, and while the Mineral Violet has already turned grey, the Cobalt Magenta hasn't changed colour.

What does it cost? Taking Jacksons www.jacksonsart.co.uk as the guide The Rowney Cobalt Magenta is £8.80p for a 15ml tube (5ml £4.50p). Winsor & Newton 14ml is £12.10p (5ml £6.10p). Daniel Smith is actually cheaper at £11.70p, Holbein is an amazing (Cobalt Violet Light) £18.70p with Old Holland £15.95p. All 15ml including Bloxx. Some eye watering prices here. Jacksons only offer Rembrandt in 5ml tubes - a reasonable £2.90p. You can get 21ml Rembrandt from others like Great Art www.greatart.co.uk but is such a large tube in this colour necessary? Bloxx costs £14.85p, Graham £10.36p (inc.20% off offer for 6 same size tubes), DaVinci £11.96p (includes 20% offer). Both these only in the UK from Lawrence who do charge for carriage. Maimeri don't list this pigment. My suggestion would be, unless you have a definite preference for a specific make, to consider either the Rowney or Rembrandt versions and also the 5ml size if it is only used  occasionally. I do have a final suggestion. The underrated German make of Lukas offer a 24ml tube costing £9.25p then you also have the -20% offer on top. This is the Lawrence deal but Lukas is also available from Great Art and possibly some others but that 24ml tube!!!