Tuesday, 10 June 2014

Complicated Cadmium

Just now there is a big debate going on in Europe concerning the use of cadmium in the manufacture of paints and pigments. Of course, for the artist, cadmium is a major player in many a colour palette, with our primary yellows and reds all coming from the use of this ingredient. So what is all the fuss about then? Well, basically it's not a health and safety issue from the point of the user, it's more about the problems and pollution that heavy metals can cause when they enter water courses. According to an interview with Michael Craine from Spectrum Paints on a recent blog post over on the Jackson's Art Supplies blog, it was stated that,

 "...one EU member maintains that by rinsing brushes in the sink, cadmium may enter the waste water treatment plants and up in the sludge. When the sludge is spread on agricultural land, growing crops absorbs the cadmium and consequently this will lead to an increased exposure to humans via food."
                                                                                     Michael Craine

Ah, it's just a bit dodgy then? Well cadmium, like all heavy metals, carries a certain level of risk to health, being toxic and carcinogenic when inhaled or consumed. So a word of warning here, don't get into the habit of putting the tip of your brush in your mouth to maintain it's tip whilst painting. Digressing here a little, this has been proven to have caused all sorts of problems in the past, when female factory workers, (the Radium Girls) painting dials on clocks using radium (to make them glow in the dark) got all kinds of mouth cancers by licking their brushes to maintain a sharp point.

Radium Girls at work

Paint manufacturers have attempted to reduce the health risks of cadmium by using pigments that have a substantially lower solubility. However, our seemingly innocuous cadmium yellow still needs to be treated with some caution. There is an ongoing public consultation currently being carried out on the European Chemicals Agency website, and artists are being invited to leave their comments.

My cadmium collection

I don't have any particular preference on brand.
Just the right colour and consistency for the job.

So, with this in mind, and following on from the recent post Paints with Added Oomph on the joys of trying out new paints, and with the potential disappearance of cadmium yellow and cadmium red from my palette, I have been researching some alternatives. First stop for valuable info was the Handprint website. Always a great source of technical information, they have dedicated wepages for a whole plethora of yellow and red paints and pigments, and it was surprise to see which colours were deemed worthy and more surprising to see which ones were not. You can also find out how to choose the right paints for you with their 5 step approach.

Hmm, finding that perfect middle

So, I started with yellow. Cadmium yellows tend to be semi-opaque rather than transparent, with different opacity levels across the manufacturers and main brands. As a first alternative, I have discovered that Hansa Yellow is considered by many to be 'the perfect yellow', being more transparent than cadmium and therefore a worthy contender. Hansa yellows do have variable lightfastness qualities across the main brands, but are considered highly useful for their transparency, clarity and mixing qualities. I don't have a this one yet, but to me, some of the choices look more lemony than a mid or primary yellow. Although, Hansa Yellow Deep ,(this link is for Daniel Smith) is a closer match, and one I would try. Perhaps you have this one already.

My current yellows

Both Daniel Smith and M. Graham make an Azo Yellow, which I hadn't heard of before. It is also considered by many to be a very good primary or mid range yellow, with a bright, clear appearance, and is a form of modern Aureolin. Aureolin in it's old guise, (along with Alizarin Crimson) has been superseded by modern chemical technology and newer product ranges. I found Aureolin to be bit on the greenish side for me, and although I have some, I rarely use it. I must admit that I like the look of the Azo Yellow, which has a nice sunny, bright, middle yellow appearance. Winsor and Newton's Winsor Yellow also appears to me to have a good primary basis with a clean, bright appeal with good transparency. So, there's a couple more to try out.

A new find for me has been the Daniel Smith Quinacridone Gold. Lots of friends have highly recommended this one, especially for mixing fabulous greens, and they were right, See the picture of my family group below and also my post, Paints with Added Oomph for the happy trials. So it's a keeper if a little more on the brown side of yellow, so not a substitute for cadmium yellow.

Of course, all paint manufacturers are reliant on certain pigments and ingredients being made available to them, and recently some pigments were discontinued, especially those used in Gamboge which ran out in 2012, and chrome yellows, it would appear have been discontinued. Of course, it is always a necessity to update the palette as chemistry progresses and we learn more about the ingredients we use.

My current reds

Now for the reds, and a slight digression first. Good old Alizarin Crimson, (yes that one again) has problems with lightfastness and newer, better, more stable alternatives are out there. I do have Alizarin Crimson, but have found myself using it less these days. A surprising alternative has been suggested. I adore Perylene Maroon, it's rich, transparent and highly staining, but I have never considered it as a replacement for Alizarin Crimson, as it is more brown, and well, maroon. Whereas alizarin is a much cooler crimson. However, I have noticed that I use my perylene more often, and it's a good mixer with blues to create reds in the cooler spectrum. Bruce MacEvoy at Handprint would appear to agree with me and endorses Preylene Maroon as a fine substitute. Bye bye Aliz'?

"...I think the affection many painters feel for alizarin crimson actually has to do with its dullness rather than its intensity, as alizarin can mix glowing, flexible flesh tones, dusky violets and silky near blacks; these painters often feel the quinacridones are too strident and bluish. For them a two paint substitution may be more desirable. I highly recommend Perylene Maroon as the best substitute for Alizarin Crimson"
                                                                                                  Bruce MacEvoy 

Alizarin and Perylene Maroon, along with Carmine.

But what about that Cadmium Red? Well, cadmium reds, like the yellows are semi-opaque, are gorgeous no doubt about it, and universally popular as there are few to match their warmth, quality, clarity and staining properties. Winsor and Newton Cadmium Red and Cadmium Red Deep are my current favourites, being reliable and rich both in mixes and on their own. Quinacridone reds are considered good middle reds, equivalent to a cadmium red medium or Pyrrol red, and I have found it to be a lighter, less intense red that is excellent in creating a superb range of purples and oranges when used in mixes. It is also quite lovely as a glaze or colour on it's own. It is also less staining than cadmium, with a greater transparency.

Pyrrole Red appears to be the colour that is being heralded by manufacturers and users as a potential match for Cadmium Red, it being less polluting, but with the intense, staining pigment so evocative of the cadmium reds. These reds are also highly recommended due to their consistency in hue, saturation and texture, although it's reported that they can be much brighter and tricky to tone down. others have suggested they actually have a dulling effect. Currently, I don't have a Pyrrol Red amongst the collection, but I would definitely like to trial one or two myself to see how it compares with my favourite cadmiums.  

The family group.

Of course, we all have our beloved yellows and reds, (perhaps you already have some of those suggested) and although not cadmium substitutes, I am happy to know that not only is my favourite Perylene Maroon a valuable choice, (and I have introduced a few new converts to the cause), but also my invaluable Schmincke Translucent Yellow, (along with Winsor and Newton Transparent Yellow and Daniel Smith Nickel Azo Yellow Dark) is amongst the most transparent yellow formulations available and therefore extremely versatile. Fantastic in glazes over greens and equally superb in mixes, I wouldn't be without mine, and have just discovered the equally amazing value of the Translucent Orange by Schmincke too.

And in case you needed any more of an endorsement to give these a go, here's the advice from Bruce MacEvoy over at Handprint again,

"PY150, (the pigment C.I name for these colours) seems to me to be a superb botanical yellow. Applied full strength, it is a yellow just on the border of brown, and makes a beautiful series of vegetable yellows, oranges and reds when mixed with a dull red or dark red violet paint. Mixed with a phthalo green, nickel azo yellow creates beautifully varied, natural yellow greens resembling the color of spring leaves and new lawns. And in tints it is a gentle floral yellow, close in hue to aureolin, the hue of many varieties of flowers. Overall, I strongly recommend you try it."
                                                                                                  Bruce MacEvoy

Others in this PY150 group also include: M.Graham Nickel Azo Yellow and Nickel Quinacridone Gold, Winsor and Newton Quinacridone Gold (hue) and Rembrandt Gamboge (hue).

Thankfully crushed beetles, clay and even cattle urine, ( for over a century, it was believed that the commonly used Indian Yellow pigment was created from the urine of cattle in India, that were fed only mango leaves and water. Allegedly, the dried urine was collected and formed into balls of pigment. This is a bit of an 'urban legend' with no real evidence. But thankfully, Indian Yellow is now made using a combination of nickel aso, hansa yellow and quinacridone burnt orange) are giving way to man made chemical compounds, to give us newer, safer, (and in some cases more fragrant) colours.

So, although Cadmium is in the current firing line, there are alternatives and good substitutes out there that may just become new favourites. Let's not get stressed here, just give them a go, ask friends for recommendations, (they are a great source of info), or you may already be a convert. Just see which ones are most useful for you. The choice is yours, (or mine, as I am off to get some more for the collection and will report back on my findings soon). 

Useful Links

Handprint: Red Watercolours - for all the technical information on the colours mentioned


Claire said...

Really interesting post Jarnie,great to research this. I have a few cadmiums still , but use them very rarely. I always use winsor red instead of cadmium red and azo yellow or winsor lemon instead of cadmium lemon, but I've always liked cadmium scarlet and cadmium yellow.

Janene said...

Thanks for all of the useful info, Jarnie! I stopped using the cadmiums awhile ago but I know they are essential pigments for many artists so it will be interesting to see how this controversy plays out. Personally, I like W&N Permanent Rose (same pigment as DS Quin Rose)as a replacement for Alizarin Crimson, although I am coming to appreciate Perylene Maroon as well. We have so many pigments to choose from these days that is it overwhelming (and always tempting to buy 'just one more')!

Elisabeth said...

Try Daniel Smith's azo yellow with their indanthrone blue for a nice, desaturated botanical green, easily tweaked. PY129 is not on many people's palettes but is very useful for mixing transparent greens. Also M. Graham's napthol red is amazing and quite transparent.

Sketchbook Squirrel said...

Thanks Claire,Janene and Elisabeth for your great suggestions and comments. Glad it's brought the topic to the fore and we are all finding some great new products and colours.

I agree Janene, there's always room for just one more :)

Oh, I am a great fan of Indan blue too Elisabeth, I love it mixed with a lemon yellow too.