A gallery of typographic and graphics design examples of rubrication, a classic pattern of using red versus black for emphasis.
created: 30 May 2019; modified: 26 Nov 2019; status: finished; confidence: certain; importance: 2
Dating back to medieval manuscripts, text has often been highlighted using a particular distinct bright red. The contrast of black and red on a white background is highly visible and striking, and this has been reused many times, in a way which I have not noticed for other colors. I call these uses rubrication and collate examples I have noticed from many time periods. This design pattern does not seem to have a widely-accepted name or be commonly discussed, so I propose extending the term “rubrication” to all instances of this pattern, not merely religious texts.
Why this rubrication design pattern? Why red, specifically, and not, say, orange or purple? Is it just a historical accident? Cross-cultural research suggests that for humans, red may be intrinsically more noticeable & has a higher contrast with black, explaining its perennial appeal as a design pattern.
Regardless, it is a beautiful design pattern which has been used in many interesting ways over the millennia, and perhaps may inspire the reader.
Red is among the classiest of colors, as a glance through fine book editions reveals. What is snazzier than a good drop cap which has been
“rubricated” (sometimes called
“printer’s red”)? And yes, rubrication is usually red—hardly ever orange, or green, or purple, or any of the other possible choices.
Rubrication is not merely coloring everything red, but a careful use of some red against mostly black in order to emphasize important elements. We have red letter days for holidays, Christians will subconsciously associate red text with the words of Jesus Christ in typesetting the New Testament, and maps or charts may highlight key destinations in red while every other location is printed in black.
Further, I noticed that these all seem to use not just red, but almost the same shade of red: a certain bright but medium red, never another shade like a pink or a deep scarlet. That might be an artifact of traditionally using iron gall ink (eventually upgrading to “minium” lead pigments) and then everyone imitating it, but once I began paying attention to red/black combinations, like the famous
“law of fives”, I began noticing it everywhere. (One place I haven’t seen rubrication used well is in predominantly black settings, such as the increasingly popular
I could imagine that being true in medieval times when rubrication started (iron gall-based rust/oxide pigments are surely extremely cheap compared to many things), but that seems like it should have stopped being a problem at least by the 1800s when synthetic dyes & inks were invented. It also wouldn’t explain the prestige of vermilion not merely as a red in general, but as a vermilion ink reserved for imperial use in calligraphy & documents in both the Byzantine & Chinese empires.
Edward Tufte, who highlights many examples in his books and is a skillful user of rubrication himself2, notes in Envisioning Information 1990 (chapter 5,
“Color and Information”, pg83–86), apropos of Byrne’s unique color-diagram book interpretation of Euclid’s Elements3:
Byrne’s colors keep in mind the knowledge to be communicated, color for information. Use of the primary colors and black provides maximum differentiation (no four colors differ more).4 This yellow, broken with orange, is darkened in value, sharpening the definition of its edge against white paper; and the blue is relatively light (on a value scale of blues), reinforcing its distance from black. In the diagrams, the least-used color is black, and it is carefully avoided for large, solid elements—adding to the overall coherence of the proofs by muting unnecessary contrasts.5
…in languages with fewer than the maximum eleven color categories, the colors followed a specific evolutionary pattern. This pattern is as follows:
- All languages contain terms for black and white.
- If a language contains 3 terms, then it contains a term for red.
- If a language contains 4 terms, then it contains a term for either green or yellow (but not both).
- If a language contains 5 terms, then it contains terms for both green and yellow.
- If a language contains 6 terms, then it contains a term for blue.
- If a language contains 7 terms, then it contains a term for brown.
- If a language contains 8 or more terms, then it contains terms for purple, pink, orange or gray.
In addition to following this evolutionary pattern absolutely, each of the languages studied also selected virtually identical focal hues for each color category present. For example, the term for“red”in each of the languages corresponded to roughly the same shade in the Munsell color system. Consequently, they posited that the cognition, or perception, of each color category is also universal.4
Are there deep evolutionary reasons for red being so important to human color vision, perhaps because red is overrepresented in nature in important things like blood or berries?7 I have to wonder why a color like green is not more psychologically important, though, as green is surely even more common than berries (which often aren’t red)—thanks to the inefficiency of chlorophyll in absorbing those particular wavelengths of visible light from our sun8—and human eyes are in fact physically most sensitive to green light in night vision. Why aren’t humans most attuned to green, the better to navigate jungles etc? (Is Rayleigh scattering involved somehow?) So this is a little puzzling.
When using white-on-black, what is the functional equivalent of red? A green? A blue? For all the traditional popularity among programmers of the classic monochrome monitor computer terminal green-on-black phosphor color scheme exemplified by the VT100—what I myself use—most dark mode designs I see currently seem to opt for a blue…↩︎
Tufte routinely uses rubrication in his graphs & sparklines to emphasize key numbers or points: his 2006 Beautiful Evidence, for example, uses red on practically every other page. The use of proprietary Bembo fonts and rubrication mean that even Tufte ads are recognizably by Tufte. (This does pose some challenges for the family of Tufte CSS packages for various formats: there are now open-source Bembo fonts, but do red links really work online? Some Tufte CSS implementations like Eric J. Wang’s go for it, and others do not.) The sheer number of Tufte uses makes it difficult to select any examples for this gallery.↩︎
Byrne’s edition is beautiful and unusual enough that there are at least two attempts at recreating it worth looking at: Slyusarev Sergey’s
“Fancy Euclid’s Elements in TeX”for PDFs; and Nicholas Rougeux’s
“Making of Byrne’s Euclid”on how he created a beautiful interactive HTML version.↩︎
Is saying that rubrication works because it ‘maximizes contrast’ question-begging?↩︎
Use of primary colors like Byrne (yellow/red/blue) highlights an additional advantage of rubrication for emphasis: it avoids problems with the most common forms of color blindness—pretty much everyone can see red or at least see the contrast with red.↩︎
While exceptions have been found to this flowchart and the Berlin & Kay results questioned, the red results (that it follows black/white darkness terms, and precedes all other colors, and red is consistently red cross-culture) appear to be supported by the subsequent data.↩︎
It’s unclear, though, why our infant brains chunk colors at all. In a 2011 study, a team led by researchers at Mount Sinai School of Medicine, in New York, found a mathematical formula that describes how inputs from the retina could result in the separation of colors into warm (white) and cool (black) tones, suggesting that the physical properties of our vision system may create natural
“fault lines”in color space.10 Other researchers speculate that colors in our environments may cluster around certain shades, such as the bright red of blood and berries, or the solid green of fields and foliage. As babies, we may be primed to pick up on these statistical regularities.
Given how wasteful that seems, one might wonder about alternatives; there might have been earlier ones, leading to the Purple Earth hypothesis. Are there better chlorophylls which could absorb more light? Possibly, the bacteriochlorophyll absorb light that plants cannot, and are one of many suggested ways to improve photosynthesis efficiency.↩︎
I was amused to discover Fabre’s cover while skimming Public Domain Review essays, as the name Fabre rang a bell—not long before, I had read
“The Sphex story: How the cognitive sciences kept repeating an old and questionable anecdote”, Keijzer 2013, criticizing the Sphex anecdote which Hofstadter & Dennett so enjoy. And imagine what phrase I ran into within the first screens of reading Fabre’s cat essay, but
“red-letter day”. The Baader-Meinhof effect‽↩︎