Look closely at almost any well-made page, printed or on screen, and you will find an invisible grid holding it together: columns, margins and gutters that everything lines up to.

Designers have used underlying structures for centuries, in the proportions of medieval manuscripts and the columns of early newspapers. The modern idea of the grid as a deliberate, flexible system came into its own with Swiss graphic design in the 1950s, and Josef Müller-Brockmann’s 1981 book “Grid Systems in Graphic Design” became its handbook.

The grid moved to screens with the web, and then had to learn to bend. A layout that works on a wide monitor must also work on a phone, so today’s grids are fluid, collapsing from many columns to one as the space shrinks.

The principle has not changed: give every element a place, and the page feels calm even when it is full.