Every page begins as a negotiation between voice and stamina. The display face gets one line to catch the eye, while the text face has to hold attention for a thousand words without ever drawing attention to itself. Get the pairing wrong and the reader feels it before they can name it: a shout followed by a mumble, or two faces that argue in every paragraph.
The old rule of thumb — pair a serif with a sans — is a reasonable starting point, but contrast is only half the story. Look instead at proportion: the height of the lowercase, the width of the o, the angle of the stress. Faces that share a skeleton will sit together comfortably even when their surfaces are wildly different. Squint at the page and see whether it still holds together.
Rhythm before ornament
Body text lives or dies on its texture. Set a paragraph at 18px with a generous measure and watch how evenly the grey settles across the column. Uneven colour — letters that clump or spaces that open into rivers — is far more tiring than any choice of style.
- Keep the measure between 55 and 75 characters.
- Let leading grow as the line gets longer.
- Check figures: 0123456789 and £1,250.00 should sit calmly in a sentence.
Headings, by contrast, can afford to be difficult. A heavy weight, a tight fit, a quirk in the ampersand — these are pleasures at 72 points that would be exhausting at twelve. That is why the pair exists at all: each face does the job the other can’t.