Dark spots in type designType 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.More Like This
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: