If you are the kind of painter who is happy to throw coffee grounds, sand or acrylic glitter onto their watercolours and then stand back and pray for a happy accident then you can happily ignore this lesson. This lesson is specifically about the qualities that individual paints have and how these qualities can be explored, so that you can make more informed choices when actually using your paints. In short, this lesson should help you control the medium rather than relying on a more or less random outcome.
If you have a quick look back at lesson 3 you will see that when the paper is stained by the watercolour you are using, much less light is reflected back from the surface and the more it is stained the duller your colour will look. Luckily, there is a very easy way of finding out if your colour is a staining colour or not. You simply lay down a medium strength, smallish patch of the colour you want to test and then once it has dried you try and wash half of it away with clean water, dabbing with a tissue to mop up any paint that comes away. If it is a strongly staining colour you will find that even after quite a bit of washing and dabbing, you will be left with a clearly stained area of paper. Obviously if you are comparing colours directly you should apply the test fairly by ‘washing and dabbing’ the same amount for each area of paint.
Here I have tested 6 useful blues that I have in my box and you will see that some stain heavily and some hardly at all.
Without doubt Winsor Blue stains most heavily followed by Antwerp and French Ultramarine. Cobalt and Indigo are only moderate strainers and Cerulean hardly stains at all.
So why does it matter whether the paint stains or not? There are two quite different issues to consider. If you are planning on doing a low key painting with dark sombre colours, perhaps a nocturne, then it would make sense to use staining colours from the start because they would naturally give a darker look to the picture. If on the other hand you were planning to lift certain areas of colour to make them lighter or to try and get back to the ‘white’ paper then it would be a hopeless task if your paper has been heavily stained. Although in theory you can leave ‘left lights’ of unpainted paper I can tell you from experience that it is surprisingly easy to miss them when laying in a wash and you then end up trying to rescue things by washing away some areas of paint. If you have used heavily staining paints from the start the task becomes hopeless.
The same exploration can be made for any or all of your colours and I have done the same thing with the reds from my box.
Alizarin Crimson is the heaviest stainer, with, Winsor Red, Scarlet Lake and Cadmium Red not far behind. Brown Madder and Rose Madder Genuine hardly stain at all.
You might be interested to know that I tend to use a mixture of Cobalt Blue and Rose Madder Genuine for some cloud shadows, particularly in evening light, precisely because the grey/purples they form retain their luminosity as neither colour stains much and I need this quality of luminosity for my skies as it helps to generate a feeling of airiness and distance. If I substituted say Alizarin Crimson to make the purple the result would generate a very glowering broody cloud shadow (useful for tropical cyclones!)
It is only really by doing the stain test that you start to get into the subtlety of the colours. For instance although Scarlet Lake looks like a nice bright orange, straight from the tube it stains so heavily that it soon loses any freshness. Whereas Brown Madder, which looks quite dark from the tube, can make lovely ‘bright’ orangy-browns when used with a bit of water.
The greens are a very interesting group to test particularly as they are needed so much in landscape painting.
Viridian green stain the most without any doubt. Olive Green and Cobalt Turquoise are moderate strainers and Winsor Emerald, Winsor Green (surprisingly) and Sap Green hardly stains at all.
So if you are looking for dark forest greens try mixing earth colours with either Viridian or Winsor green which will give you rich dark colours, or you could mix your dark greens by mixing yellows with Indigo or Paynes Grey
Cobalt Turquoise and Winsor Emerald can be usefully mixed with yellow/earth colours to give a feeling of sunlight.
The set of warm tertiary colours are also interesting to look at too as they are often used in combinations with various blues when painting landscapes
Burnt Umber, Burnt Siena and Gold Ochre stain quite heavily, whereas Raw Umber and Raw Sienna hardly stain at all, don’t ask me why, but it is certainly useful to know when painting.
Vandyke Brown, which is a good useful basic brown does not stain quite as much as you might expect, and can be used with blues to make greys, and reds to make rich warm browns.
I have included Yellow Ochre in this group because although it is a ‘yellow’ it is very much a tertiary yellow and fits well with the ‘earth’ colours. It is only a moderate stainer and I often use it with plenty of water in warm skies.
The Yellows are also an interesting set to examine because although several of them look quite similar when first out of the tube they behave quite differently.
Of the set it is definitely Cadmium Yellow Pale which stains the most heavily so although it is a ‘bright’ yellow it can make dull mixtures if not used carefully.
New Gamboge, Aureolin and Winsor Yellow Deep stain only moderately with Winsor Yellow Deep being the warmest of the three. And Winsor Yellow, and Naples Yellow hardly stain at all and so can be used where ‘light’ high-key colours are needed
If you have any other colours in your box which I have not mentioned it is easy enough to test for staining and it is something that can very usefully be done when you are in a curious mood on a wet Sunday afternoon (and it’s more interesting than painting the hall!) It’s well worth the effort because once you know how each colour stains (or not) you will find yourself reaching for the most appropriate colour. Remember, if you use a staining colour you need to know it’s going in the right place because even if you try your best to scrub it away there will always be a ‘ghost’ of the colour visible.
In the next lesson I am going to look at the qualities of Transparency and Opacity and how they influence the behaviour of the paint and how you can use this knowledge to control the overall ‘feel’ of the painting.