Moiré
Lines

The eye is a poor counter of lines and an excellent detector of difference. Hold two gratings of nearly equal pitch against the window and you will not see fourteen hundred rules; you will see six broad bands sliding like weather. Those bands are not printed anywhere. They are the arithmetic of the two plates, made visible because your retina insists on averaging.

Printers knew this before physicists named it. A halftone screen laid at the wrong angle against a previous pass produced a rosette that no amount of ink density could argue with, and the sheet went in the bin. What was waste on the press floor became, for a decade of poster designers in Basel and Osaka, the whole point.

We are interested in the moment of legibility. As the angle between plates narrows, the beat period stretches until a single fringe is wider than a letterform — and the word, which was there all along, resolves. Scroll this page and you perform that narrowing yourself: each heading sits detuned until it reaches the centre of your view, where the plates come into register and the text finally speaks.

The reverse is equally useful. A heading that dissolves as it leaves is a heading that knows its own duration. Nothing on this page is permanent; everything is in phase for exactly as long as you look at it.