Colour guides
Before the engraver touched a film, someone had already decided what percentage of cyan, magenta, yellow and black went into every patch of sky, every face, every shadow. That decision was recorded on paper, by hand, in paint.
The Guide Sheet and What It Did
A colour guide — sometimes called a colour indication or colour overlay — was a physical document prepared by the colourist and handed directly to the engraver or colour separator. Its job was translation: turning the artist's line art into a set of numerical instructions that a human could cut into film and a press could reproduce. Without it, the separator had nothing but guesswork.
The mechanics were straightforward, if painstaking. A colourist would work on a photographic stat or a blueline print of the original inked page — a same-size or reduced reproduction, never the original art itself. Using opaque gouache or watercolour, they filled each area with a mixed paint colour intended to approximate the desired print result. In the margin, or directly on the area, they wrote the percentages: C50 M0 Y100 K0 for a mid-tone green, or C0 M100 Y100 K0 for a red. These referred to the four process inks — cyan, magenta, yellow and black — and the four-colour separation process that would render them as overlapping halftone screens on the printed page.
On the record
Process and materials
- 01Colour guide — a hand-painted sheet, same size or reduced, showing the colourist's paint approximation of each printed tone, with CMYK percentages written on each area; handed to the engraver as a specification
- 02Rubylith / Amberlith — red or amber masking film cut by hand; the separator peeled areas to expose or block each ink's screen
- 03Percentage steps — American comic production standardly used 25%, 50% and 100% values of cyan, magenta and yellow, yielding 64 available colours
- 04Blueline or stat — a photographic reproduction of the inked page used as the guide surface; the original art was never marked
The separator then used the guide to hand-cut Rubylith or Amberlith masking film, one layer per ink colour. Each piece of film corresponded to a percentage value: the cutter would leave a given area masked or open depending on what percentage of that ink was required. A 50 per cent screen meant the dots covered half the paper; 100 per cent meant solid ink. The Ben-Day dot patterns produced by this process were not decorative choices — they were the physical consequence of printing flat-percentage tints at screen angles.
Limits the Colourist Worked Within
The available palette was narrow by modern standards. Because comic pages were printed on newsprint using letterpress equipment, the practical range of percentage steps was coarse. Standard comic colour guides in the American tradition worked from a 64-colour palette built from combinations of 25, 50 and 100 per cent values of the three chromatic inks, with black used separately for the line art itself. That is not 64 mixed tones so much as 64 available addresses in a fixed grid. The Bibliothèque nationale de France holds European album originals that show how differently bande dessinée colourists worked within their own technical constraints — the album format, printed on better stock than American newsprint, permitted finer screen rulings and richer colour density.
Using opaque gouache or watercolour, they filled each area with a mixed paint colour intended to approximate the desired print result.
In the European tradition, the colourist's role carried more visible weight. Studios working for publishers like Casterman and Dupuis often employed dedicated colourists whose names appeared in the credits. The guide was still a technical document, but the paper it was painted on was expected to be a considered piece of work, not a set of shorthand notes. Hergé's albums, coloured in collaboration with his studio, were produced with guides that functioned almost as finished artworks in their own right — meticulous enough that the separation could be made with very little interpretive latitude left to the engraver.
After the Guide Left the Room
Once the separator had the films and the guide had served its purpose, the original painted sheet was generally discarded. Original colour guides are consequently rare as archival objects; they were production documents, not art objects, and the industry treated them accordingly. Surviving examples tend to come from publishers or studios that happened to retain their production files, or from individual colourists who held on to their own work.
On the record
Chronology
- 01American 64-colour palette in use through the mid-twentieth century newsprint era
- 02European album colourists worked with finer screen rulings on better paper stock from the album trade's mid-century consolidation
- 03Digital colour software displaced painted guides through the late 1980s–1990s
The digital transition of the late 1980s and 1990s made the painted guide obsolete. Software allowed colourists to specify values directly and pass a digital file to the separator. The percentage grid survived into digital colour — it simply became CMYK fields in a software palette rather than paint mixed by hand and a number written in the margin of a stat.
Named in this entry
People and houses
Cartoonist, 1907–1983
Hergé
His albums at Casterman in Tournai set the format other album houses matched.