Set on twelve, read on seven

A grid is not the columns. It is the agreement that everything on the page starts and stops in the same few places, which is what lets a reader stop noticing the layout and start reading.

The margin is not a gutter

They are different measurements doing different jobs. A gutter holds two columns of type apart. A margin holds the type off the trimmed edge of the sheet, and it wants to be several times larger.

The band bleeds, the grid does not

A section spans the whole window so it can carry a ground to the edges. The tracks sit inside it, inset by the margin. Put the margin on the section instead and nothing can ever bleed.

A granite cliff above a river, with conifers along both banks — Seven columns. Wide enough to carry a landscape, and it leaves five for something to sit beside it.

Thirds, halves and quarters

Twelve divides by two, three, four and six, which is every division an editorial page actually asks for. Ten looks tidier on paper and cannot do thirds, which you discover on the first spread that wants three of anything.

A fjord far below, seen from a clifftop where people are standing on the rock — Four columns

A red sandstone canyon lit low by the sun, under broken cloud — Four columns

A single track road winding between steep green hills under low cloud — Four columns

The rules are drawn from the grid, not alongside it

An overlay that is its own repeating gradient is correct on the day it is made and wrong after the first change to a gutter. This one reads the same three custom properties the layout does, so it cannot describe a grid other than the one it is sitting on.

Press the control to see it.

A waterfall dropping from a cliff into a conifer forest in mist — Full bleed inside the margin. The picture spans every track, which is not the same as spanning the window.

Measure

Type does not become more readable as its column gets wider. Past about seventy-five characters the eye loses the start of the next line, and a span of seven columns on a wide screen is well past that. So body copy takes a measure as well as a span, and the two are not the same instruction.

68ch, held