Mixing CMY primaries
The following sequence show how the three primaries may be combined to produce an enormous range of colour. To start with, white may be added to each primary to give an infinite gradation, but, for the sake of simplicity, only four steps for each primary are shown in the colour chart below. The number of steps could be increased as far as desired. Paint on the palette usually resembles a continuous gradient.
The combination of Cyan and Magenta with Yellow added in four steps.
Strong colours are produced along the sides of each block of 16, but also a range of subtle colours appear within. In each group one colour is approximately neutral – either white, black or grey. These colours have been marked with a dot.
Although this arrangement is an effective way in which to show the possibilities, it is not convenient for a painter. The eye and brain tends to classify colours into hue groups – red, orange, yellow, green, blue and so on – rather than into precise amounts of the three primaries. So mixing and matching colours is easier to carry out if a different arrangement of colours is kept in mind – one more in keeping with the way in which the mind normally operates. Such arrangements are known as ‘colour models’, of which there are a great many to choose from.
COLOUR PRINTING
Pupil’s view of what had been achieved in the past and what could be achieved in the future, was based on little more than what they had been able to see around them in local workshops, in churches, or in the houses of patrons (supposing they were lucky enough to be invited). Even as recently as 1800, Constable was thrilled to be invited to a grand house where he dropped all his other concerns in order to spend weeks copying. Travel was difficult and expensive and artists conception of artistic possibilities was very limited.
This changed drastically in the 18thC with the advent of public museums , and in the 19thC with better public access to these museums, and with the invention of photography. This allowed reproductions of works of art to be passed around, and later to be reproduced in books and magazines. Now, with the Internet, one does not even have to visit a library in order to see superb reproductions of the best of every style from every period, from the whole world.
With the future of art depending so much on these reproductions, it may be worth having some idea of how these reproductions are made.
1893, L. Prang & Co.
By Harlow, Louis K. (Louis Kinney), 1850-1913 (artist); L. Prang & Co. (publisher) – Flickr: First lithographic print in the primary triad of colors, Public Domain, https://commons.wikimedia.org/w/index.php?curid=15991600
This early three colour process was taken further when a suitable Magenta pigment became available. This gave rise to a wider range of strong colours than the Red above. The three inks were not perfectly transparent, so they did not make a pure black when printed together. In order to make up for this, a black was added, called a Key colour. So, in 1932, the Cyan, Magenta, Yellow, Key (CMYK) came into being, and has remained essentially unchanged ever since.