Dark spots in type design

Type design is all about balancing the black versus white to create a consistent texture. One of the—perhaps more obscure—principles of creating well balanced type is a consistent stroke weight in certain areas—particularly in the joins. This is true even for simple geometric typefaces of which you probably wouldn't expect it if you're not familiar with dark spots.

Ink traps

Dark spots occur in places where two strokes meet and this is particularly true when two strokes meet at a sharp angle. When two strokes meet there is a weight build-up which should be optically adjusted. The letter 'M' for example usually has three dark spots, one for each bend. Adding so-called ink traps [picture below] can get rid of these dark spots but it's quite an obtrusive method. essentially you add an extra vector point in the narrow negative space area and simply widen the area to give the black room to "breathe".




Ink traps are mainly reserved for two things:

To avoid the flow of ink into narrow negative spaces when using fast and cheap printing techniques such as newspaper printing.
Nowadays ink traps are often added as a style; a sort of decorative element.

If you want to add ink traps to your typeface for functional reasons rather than aesthetics you have to consider at what point size your typeface will be used. For display typefaces you would probably add relatively small ink traps compared to text typefaces as the flow of ink in smaller type is much more disruptive than it is for big type.

It should also be noted that not all typefaces require dark spots to be avoided/removed. In case of DIN for example these dark spots are actually part of the typeface's aesthetic. In case of a typeface like Futura however the weight of the strokes need to be consistent so it's good to avoid dark spots in this case. Besides, it's fine if you want your typeface to feature dark spots but it obviously should be a conscious choice and shouldn't occur due to ignorance.

Removing dark spots

So how should dark spots be avoided without using ink traps? The principle doesn't differ much from ink traps. Instead of widening the narrow negative space you make it longer. You will often have to add a few extra vector points so you can make the negative area go inwards into the letter a tiny bit besides elongating it. Look at the image below to see the difference and particularly note the vector points in regard to the guidelines.




And that's it really! I assure you that by avoiding these dark spots when appropriate will improve your typefaces instantly. It will make the texture of your typeface more consistent and in effect will improve the reading experience.


Written by MartinSilvertant.