Only that is limited has form. The contour of a letter, the outline of a shape, the frame of an image—they all organise how we see. An edge can be crisp, mechanical, exact, or it can be soft, fading, porous. It determines the character of form: a brutalist block versus a blurred gradient, a hard crop versus a feathered dissolve. Design can be many things. Among others it will always be the act of defining, questioning and—in some cases—shifting boundaries. Its approach to boundaries does not stem from a subordinate, theoretical principle, but is given on a practical level. Edges are both a tool and an execution here. We use them to structure attention. Figure and ground. Edges are thresholds between positive and negative space.

The edge is everywhere. Drawing type is creating edges. They are defined by Bézier points, by on-curve and off-curve decisions that shape every contour. A single edge adjustment can change the typeface—terminals cut vertically or diagonally, shoulders softened or squared. Edges define stroke modulation: the crisp joins of GT Sectra versus the flaring warmth of GT Flaire. Optical correction is often about edges: overshoot ensures that curved edges feel aligned with flat ones; hinting ensures edges rasterise well on screen. Sidebearings can be seen or not seen as invisible edges. Edges that create the overall rhythm in the sequence of characters. Edges are where black meets white, where form becomes legible.