How point tags decide where serifs land in Font by Zaweba

Adding serifs to a whole alphabet with one switch sounds like magic. It works because every letter knows where its stem ends are. That knowledge comes from point tags, a quiet part of Font by Zaweba that decides where components attach.

Each letter in the base alphabet is a skeleton: a centre line made of points that a pen strokes along. Every point on that skeleton carries a tag describing what kind of point it is. The tags are stem-end, corners, horizontal, vertical, curve, bowl, junction and stem-mid. Points are tagged automatically, so in most cases you never need to think about them.

What the tags are for

Components look for particular tags. Serifs attach to stem ends, so a point tagged stem-end at the top of an l gets a serif and a point at a junction in the middle of an h doesn't. Decorations can be placed in several ways, for example at the centre or along strokes, and they use the tags to know where those places are. When you choose straight stems only or every stem end including curves for serifs, the tags tell Font which ends are which.

That's why a single change in the style stack can restyle every letter consistently. The tags carry the meaning, and the components follow the meaning rather than a fixed position.

When you need to change a tag

Automatic tagging gets almost everything right, but type is full of judgement calls. Is the end of the tail on a lowercase t a stem end that should get a serif, or a curve that shouldn't? Different typefaces answer differently. If a serif or decoration lands somewhere you don't want it, or fails to appear where you do, the tag on that point is usually the reason.

In the glyph editor you can select a point and change its tag. Change a curve to a stem-end and a serif will attach there. Change a stem-end to something else and the serif goes away. This works per glyph, so you can make choices letter by letter.

If you've made a mess of a glyph's tags, or edited the skeleton so much that the old tags no longer fit, re-run auto-tag. It looks at the glyph afresh and tags its points again.

Other point settings

The same side panel holds a few related settings for a selected point. You can keep its edge on a metric line, which keeps the edge of the stroke aligned with the baseline, x-height or cap height so it doesn't drift above or below the line when weight changes. You can choose the end cut, which decides how the stroke ends at that point. And you can set the stroke thickness at that point, which is how you make a stroke swell or taper by hand.

These settings are worth knowing for careful work. Keeping edges on metric lines is what makes a row of letters look level. Thickness by point lets you give a single letter more character without leaving the skeleton approach.

A sensible way to work

Do the broad styling first. Choose a preset or build up the stack, add your serifs or decorations, and look at the whole alphabet in the glyphs grid. Only then go hunting for letters where a component lands oddly. Fixing tags too early can be wasted effort if you later change serif style or turn decorations off.

When you do fix a tag, check the result in the live preview with real words, not just the single letter. A serif that looks right on its own can look out of place next to its neighbours.

Remember that edited glyphs show up under the Edited filter in the glyphs grid, and that Revert to base puts a glyph back to its starting form if your changes don't work out.

Point tags are the reason a font made with sliders can still look considered. Most of the time Font by Zaweba handles them for you, and when you want a different answer for a particular letter, the choice is a few clicks away.