Airbus B612 Cockpit Font

It's interesting to me that those fonts seem to include ink traps: curious if this has anything to do with the display tech that's used in the cockpit

I had not heard of ink traps. Basically, they are characters that try to account for ink bleeding. By putting more negative space in corners, for example. https://en.wikipedia.org/wiki/Ink_trap

But that gives me the impression it would have nothing to do with displays. And makes it a pretty curious choice.

Although I personally dont see any ink traps from the font linked in the comments https://fonts.google.com/specimen/B612

Ooh, great question. I guess “ink” traps would actually make sense for CRT displays due to phosphor bleed. (See the design of the VT100 font.) However, according to Wikipedia Airbus started using LCDs well before this font was made.

Set font size slider to 300px and you will notice them. I'd love to see the study that decided this was the right move. For a digital display its just noise and won't even render correctly at small sizes without a high dpi display. I doubt they would do this just for stylistic purposes. Seems like a very odd decision to me.

It seems far too deliberate not to be so. Wonder about the reason too. Maybe dual-use with printouts?

Edit: I found their reasoning:

"Moreover, activity analysis has highlighted possible impairment in reading context: variations of light and viewing angle, high cognitive load for the pilot etc�

So, B612 has created a concept of increased legibility of shape for less ideal situations and associated methods of mark corrections, to optimise the final rendering of the text and on-screen reading, particularly with the use of incises and ‘light-traps’ .

An incise is a small serif which interrupts the regularity of the vertical line: here it allows to accentuate the clarity of the leading stroke (top part) of the vertical stem 8 to avoid it being rounded off when antialiasing.

The principle of ‘ink traps’ has existed as long as typography has: it is a small indentation at the junction of letter strokes which ‘traps’ the ink on small characters, so that it doesn't block the junction and affect the legibility. In the case of B612, the ‘light traps’ accentuate the counterforms 7, particularly for the sharp angles� The indenta- tions are always well distinguished, even at a small size, and the contrast between the different strokes of the character is reinforced."

From page 8 of: https://github.com/polarsys/b612/blob/master/docs/B612-Leafl...

The doc also has a photo of their experimental test environment (unsurprisingly: a cockpit) and info on the test process.

That stood out to me as well. Bell Centennial† used that for phonebooks; here I suspect the light-on-dark display has some visual bleeding that this compensates for, especially for tired pilots.

† https://en.wikipedia.org/wiki/Bell_Centennial

I didn’t know about ink traps, but I did notice them right away in the sample images. I was guessing that it would help increase legibility when it was embossed or in raised printing on a physical button.

Stuff that are on display can also be printed (on board in the cockpit) for whatever reasons the pilots decide.

I thought that the printed were using thermal printing (for which I'm not sure the ink traps apply) but maybe not all of them.

The leaflet (https://github.com/polarsys/b612/blob/master/docs/B612-Leafl...) explains the design thinking behind this. They call them "light traps", though I'm not totally convinced they work well when antialiasing is used.

If the font is used primarily as light on black, then light bleeds analogously to how ink does, albeit via a different mechanism. Whether on the screen itself (like CRT) or on our retina.

I wonder if it’s a mitigation for common visual conditions or for better viewing in high-vibration environments?

Firmware updates could account for this font being used on much earlier hardware though?

The monitors (or DUs for “display unit”) could remain old but the underlying computers could’ve been upgraded.

Seems like Page 8 in the PDF/leaflet from the repository talks about it:

> The principle of ‘ink traps’ has existed as long as typography has: it is a small indentation at the junction of letter strokes which ‘traps’ the ink on small characters, so that it doesn't block the junction and affect the legibility. In the case of B612, the ‘light traps’ accentuate the counterforms 7, particularly for the sharp angles� The indentations are always well distinguished, even at a small size, and the contrast between the different strokes of the character is reinforced.

> An incise is a small serif which interrupts the regularity of the vertical line: here it allows to accentuate the clarity of the leading stroke (top part) of the vertical stem 8 to avoid it being rounded off when antialiasing.

Maybe it's beneficial from a human factors perspective to have one font for printouts and screens?