SDC Archive – Comic Computer
COMIC
The first colour mixing computer
In 1958, Davidson and Hemmendinger, founders of a small company specializing in colour measurement and standards, introduced a pioneering device called the COMIC (Colorant Mixture Computer). This was the first practical computer designed to calculate the precise mixture of dyes or paints needed to match a specific colour sample—an innovation that transformed the colouration industry.
Before the COMIC, colour matching was mostly a manual process, relying on expert colourists to mix dyes by trial and error. The COMIC automated this by using an analog computer to solve sets of simultaneous equations derived from the Kubelka-Munk theory, a fundamental mathematical model in colour science.
The Kubelka-Munk theory describes how light interacts with a layer of coloured material, such as dyed fabric or paint. It models the absorption and scattering of light within the material using two key parameters: the absorption coefficient (K) and the scattering coefficient (S). These parameters relate to how much light is absorbed by the dyes and how much is scattered by the material’s surface. Using these coefficients, the theory predicts the reflectance of a coloured surface at different wavelengths of light.
The COMIC used reflectance curves—measurements of how much light the sample reflects across various wavelengths—as input. It then applied algorithms based on Kubelka-Munk equations to calculate the individual absorption and scattering coefficients for each dye in a mixture. By solving the resulting system of simultaneous equations, the computer determined the exact proportions of each dye needed to reproduce the target colour. This process was especially valuable for solving the problem of metamerism, where two colours can look identical under one light source but different under another due to differences in their spectral reflectance. The COMIC could analyze and minimize these differences, producing more reliable colour matches. By the 1960s, about 200 COMIC units were sold worldwide, primarily to the textile industry. Early versions were large and noisy, but later models integrated early digital electronics and featured an oscilloscope display. This display visualized the difference between the target sample and the computed dye mixture by showing a grid of dots—if all the dots aligned, it indicated a successful match in reflectance properties.
The COMIC was revolutionary, speeding up colour matching, reducing costs, and greatly improving accuracy. Its mathematical and automated approach paved the way for modern digital colour matching systems used in printing, photography, and display technologies.
Thanks to Davidson and Hemmendinger’s innovation, colour matching evolved from a craft into a precise science, enabling consistent and efficient colour reproduction across industries.
Take a look at the COMIC that forms part of the SDC Textile Collection.
Davidson & Hemmendinger held a colour physics course in the UK in 1966 with presenters Hugh R Davidson, Richard ( Dick ) Landry and Tony Perry as training for operating the COMIC 1 analogue colour computer. Later a similar analogue computer was developed in the UK by Redifon with automated transfer of data from the spectrophotometer. It also used a variant of the Kubelka-Munk equation developed by Ambazumian and Chandrasekhar which took into account the small amount of light scattered before absorption into the coloured substrate. The modification was incorporated into the calculation by Dr A E Cutler of Redifon and known as the ‘C’ Function variant. There were limitations using an analogue system and so digital systems were later developed such as COMIC 11 with large integrating sphere spectrophotometer Color Eye, IBM 1130 with Pretema FS3A spectrophotometer, and the ICI Instrumental Match Prediction
( IMP ) system using a ColorMaster MkV Tristimulus Colorimeter for RGB data input to a Elliot 803 computer.
Peter Collishaw C.Col FSDC.