Rag

Set a paragraph flush left and the right side ends wherever each line happens to end. That edge is the rag, and it is the normal condition of text on screens: the alternative is justified text, which buys a straight second margin by stretching the word spaces and opening rivers down the column. A rag is not a defect to be fixed. It is a surface with a shape, and the only question is whether the shape is quiet.

Two shapes are worth learning to see. A hole is two short lines side by side, which punches a notch into the column that the eye finds before it finds the words. A staircase is a run of lines stepping evenly in or out, long, short, long, short, which reads as a pattern and pulls attention to the margin. A third is a single very short line, a widow at the end of a paragraph, short enough to look like a mistake. What all three share is that they look deliberate when nothing about them was.

Tuning a rag is line-break work, and there is more of it available than most people use. Hyphenation gives the breaker more places to go, so the lines even out instead of lurching. A non-breaking space glues a number to its unit or a name to its title so they cannot be split. text-wrap: balance and text-wrap: pretty hand the whole decision to the browser, the first evening the lines of a heading and the second protecting the last line of a paragraph. A hand-placed break is the last resort, because it is a decision made at one width, and on the web the width changes.

The craft judgement is how deep the rag should be. A very shallow rag, where every line ends within a few characters of the last, starts to read as justified text without the benefits, and typographers push it deeper on purpose so the edge is clearly informal. A very deep rag makes each line a different journey for the eye. The usual advice is to work at a sensible measure first, since most bad rags are a symptom of a column that is too narrow, then read the edge with the page turned sideways or squinted at, which is how the shapes show up when the words stop being readable.