On Designing a Font


I did some work recently which needed the creation of a font, and it made me realise just how much work was involved in that seemingly easy task. Then it occurred to me that my experience might be useful to people who were on their first steps in graphic design.

The Brief

The brief was for a font using a matrix of light-emitting diodes to display price of fuel at petrol stations.

The Planning

High-level Factors

There were some high-level factors to be considered when designing the font:

  • The capabilities of the technology
  • The importance of readability
  • It forms part of the organisation’s public image

The Technology

Each price is displayed on a single sign, with 32 pixels vertically and 80 pixels horizontally. Each pixel is either completely black or is fully on. This meant that anti-aliasing techniques were no available.

Readability And Public Image

Reading printed material is usually done under lighting conditions that are at least good. One thinks of magazines in things like waiting rooms. However, lighting conditions on the public roads can be far from ideal. At the very least, we have:

  • fog, rain, hail and smoke
  • the sun directly behind the sign
  • the sun reflecting off the front of the sign
  • dirty windscreens
  • vehicle speed, at or above the open road speed limit of 110 kph
  • driver or passenger eyesight

Each glyph needs to be instantly recognisable. This meant that it needed to be plain and simple, something along the lines of Arial. Anything along the lines of a comic font would not be acceptable.

Each glyph needed to be as large as possible. This was to maximise the use of the available “real-estate” on each sign. This mean that some of glyphs look a little narrow, but this was considered acceptable by the client.

All the digits needed to be the same width, otherwise the glyphs on the various fuels would not line up vertically. Anybody who has seen a proportional font used in such a context such as this will know just how awful it looks. There was one exception to this: the decimal point. Having a narrower glyph for this, it allowed the other glyphs to be wider, this slightly reducing the squashed appearance.

A consequence of simplicity is that it ruled out seriphs. There was one exception to this, being the number “1”. By having simple seriphs on 1 it kept the black space between the glyphs as even as possible, an important consideration for readability and attractiveness.

I have seen a seriph font on other matrix displays using the same display. It seemed that the font designer had attempted to implement Times New Roman. Admittedly, the display in question had many more pixels both vertically and horizontally, but the overall result was still rather unpleasant to my eye: it looked very “fussy”.

Some Remarks on Individual Glyphs

Another fuel supplier has glyphs where the “6” and the “9” have tails that come back below well below the top and bottom lines: they both curl back down to the loop in the glyph. Under adverse lighting conditions, they could be mistaken for an “8”. There was also the business requirement to assist in differentiating the client from its competitors. Couple this with the impossibility of using anti-aliasing techniques, and this means that the tails of the “6” and “9” are straighter rather than curved. While they may look slightly unusual, they are nevertheless instantly recognisable. The same two glyphs have their loops offset from the midline: the loops are one pixel width short of the midline. Again, this reduces the potential for visual confusion with the “8”.

Similar comments apply to the glyphs “5” and “6”. By minimising the rise at the bottom-left of the “5” it helps to provide visual distinction between these two glyphs. The fact that the loop of the “6” is smaller than the “5” also helps.

The glyph “3” also needed to be made very distinct from “8”. As with the “5”, minimising the tails at the top and bottom of the glyph helped here.

My first thought with the “1” was to place the riser at the midpoint of the bottom serif. The result looked as is if it was going to fall over to the left. To restore the centre of gravity, I moved the riser one pixel to the right.

The Final Result

This is what is looks like “out in the field”:




I am indebted to the following organisations for their support in this work:

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