I’m just curious if there’s a common explanation for something I’ve noticed with some letters I’m working on.
When I use the preview button in Glyphs to look at my letters they seem to look much better and stronger when I view them as white text on a black background instead of black text on a white background.
Is there a reason for this? Does it mean I need to make my letters slightly bolder (because white letters on black generally appear heavier than when viewed as black on white).
Just wondering if anyone had some general insights.
Usually white on black in print looks weaker, because black is ink or toner and can intrude white area. Generally speaking, it is good to use slightly heavier weight for white text on coloured background because of the ink spread issue.
Now, on LCD screen, white pixel looks stronger because it emits more light than black ones, so you can use the same weight or perhaps thinner one than in black on white.
What can a typeface designer do? Make multiple “grades”, slightly different in robustness (hairline thickness), to compensate for the difference. Or just make a typeface available in several different weights.
There is an optical phenomenon where bright things always influence neighboring dark things in our field of vision. An activated retina cell (=bright) will affect surrounding cells, effectively making white-on-black appear a little larger than black-on-white. Ink spread compensates to some degree, ironically, but both effects in combination, of course, deteriorate the shape of the letter. For a good introduction, you can watch this presentation by Erik van Blokland: http://vimeo.com/70414929