tufte-chartjunklisted

# Chartjunk ## Overview Chartjunk is any graphical element that does not communicate data — it burns ink, area, and viewer attention while adding nothing to meaning. Tufte sorts it into three kinds: **vibrations** (optical interference from busy patterns), **grids** (reference lines that overpower the data they support), and **ducks** (decoration that becomes, or buries, the data). The governing law is that a graphic succeeds or fails on its content, gracefully displayed: ornament can amplify a dull graphic's failure but has never rescued a thin data set from its own emptiness. The practical test is therefore subtractive — strip every mark that does not encode data or serve as a minimal navigational aid, then see what is lost. --- ## §1. Vibrations — Optical Interference from Busy Patterns A vibration is a perceptual artifact: dense, regular, high-contrast patterns applied to a graphic make the eye see shimmer, motion, or depth that is not in the data. The dominant source is **moiré** — two or more fine regular patterns (crosshatching, diagonal hatching, dot screens) overlaid or printed close together produce an unstable, eye-straining flicker. Moiré is unintentional optical art: the same effect 1960s Op artists pursued on purpose, smuggled into statistical graphics by default fill patterns. ### Mechanism The visual system reads closely spaced alternating lines as movement or relief — a low-level artifact, not information. Adjacent active lines also imply forms that were