Peggy und Marco Lachmann-Anke

Sometimes people have questions about materials, methods or other matters related to painting, and they do not find answers immediately. In this way I want to do my best to answer these questions. Not that I know everything, but it intrigues me to look things up and find answers. Art is “sharing”, so why not share what I know about materials and the like. Feel free to ask any questions via the contact form or via

Question: Can you also buy rough water colour paper made from cellulose and does this come in different thicknesses?


My answer: Of course you can buy water colour paper made from cellulose in the various versions and different thicknesses (weight per m²). In addition to cellulose paper, there is of course also 100% cotton and even a mixture of cotton and cellulose.

Question : By mixing primary colours you get secondary colours. I read somewhere that you get tertiary colours by making them darker or lighter, but then I read that you get tertiary colours by mixing secondary colours.

My answer: This question is a bit cumbersome to answer because several things are mixed up here. There is the colour mixing and the colour tone. Even in primary education we learned that there are traditionally three primary colours, namely yellow, red and blue. If you mix these three colours, in theory you get black. Everyone knows that if you mix two primary colours you get a different colour. Red + Yellow = Orange. Blue + Yellow = Green, Red + Blue = purple. Orange Green and Purple are thus the secondary colours. If you mix a secondary colour with a primary colour you get a tertiary colour. For example, green with yellow results in yellow-green.


If you mix two secondary colours you often get a muddy colour. Dull tending to brownish tones. That is why it is important to always test your mixing colours. This is all very nice theory, but in practice it is quite different.

A first difficulty is what is primary blue, red and yellow. There are so many types of blues, yellows and reds that one can no longer see the wood for the trees. What is important when mixing colours is that the primary colours have to be mono pigments; if you start with the wrong basis you will go completely wrong and never achieve the desired result.


I made Johannes Itten's colour circle with Sennelier L'aquarelle and used Real Cadmium Yellow Lemon (535 PY35), Real Cadmium Red Light (605 PR 108) and Ultramarine Dark (315 PB29). The secondary colours Orange and Green were correct, but the violet tints were not correct at all, tending more towards brown than towards purple. However, I did everything that theory tells me to do and made sure that the primary colours were mono pigments. The conclusion was that the primary Blue and Red that I used were not correct.

So what are the correct primary colours? That's the difficulty, what are the right primary colours...very difficult to determine because no manufacturer is clear about that, nor Sennelier, White Nights or Daler Rowney with a clear answer. Those are the brands I use. Every manufacturer has its own opinion about primary colours and that's where the cat comes in. It is by trying it out myself and doing further research that I came to the conclusion that Johannes Itten's colour wheel is correct in theory, but that practice is not so very clear. Some people even dare to say that Itten's colour wheel is outdated and incorrect. Is it? I don't think so. The theory is completely correct, but implementing it is a different matter. After many searches I came to the conclusion that one should in fact look for a blue that tends towards cyan and a red that is pinkish red (quinacridones), then one gets a more correct colour wheel. The colour circle below is a second attempt and there I used other primary colours, namely: Primary yellow 574 (Py74), madder 690 (PV19) Real cobalt blue 307 (PB28)

I will now answer the second part of the question, namely mixing the colours with white or black or mixing white and black (shades of grey). It is not the case that a secondary colour mixed with white, black or grey becomes a tertiary colour. In fact, the colour (e.g. secondary green) remains green, but the tint of the colour is changed.


By adding white the colour will become lighter, by adding black darker, by adding grey another range of colours is obtained.

Adding 1% white results in pastel shades, adding 1% black results in shadow colours, adding greys results in grey colours.


Thus: colour tone = the pure colour without the addition of black, white or grey. This can be an infinite number of colours, the 3 primary colours, 3 secondary colours, 6 tertiary colours and all blends of these.


Colour shade = a mixture of the basic colour with black, white or grey.


So hopefully you can do something with this info, enjoy mixing colours, a recommendation in the painting studio is to buy a colour wheel. This is a handy tool for artists. It can be used to test which colours go together or to help create the right colour combinations. Here you can immediately see the contrasting colours and also the warm and cold colours, more about that later.