We have already dealt with the problem of overall mass. A similar but distinct issue is that of tiny elements or thin lines, even when found in a logo that has sufficient overall mass.
All kinds of printing, be it offset, digital, laser or ink jet, have a similar drawback. I call it Ink Creep: the ink from the bigger object fills in fine negative lines to some degree. If the lines are substantial enough, the line survives this minute encroachment. On the other hand, if the line is thin, it can be compromised or filled in. This is why experienced designers don’t use type with small serifs in reverse: the serifs fill in. Fine reversed lines in a logo are subject to a similar fate. Of course, positive lines in a logo become negative lines when the logo is reversed.
This problem is not eliminated in the digital world. We view all digital media through a grid of pixels. Admittedly, the grids are getting finer as screen resolutions for electronic devices go up. Regardless, Pixel Mush reasserts itself. To review, Pixel Mush happens when shapes or lines are so small that they cannot be rendered with a pixel in the solid identity color or solid background color. If the identity colors are black and white, edges will be anti-aliased, which means that gray pixels are used on the edge to disguise the pixel grid. Anti-aliasing gives a smoother edge to elements on the screen and hides the “jaggies.” But this useful technological visual help is a double-edged sword. In a black logo on a white background, very thin white lines may be rendered only in gray because the lines aren’t wide enough for any pixels to be completely white or black. In a series of thin lines or gaps, lines can appear darker or lighter due to the number of pixels that make them up respectively.
This principle applies to typography as well, and is why fonts in the Didone family (such as Bodoni, Modern, Didot, etc.) are so seldom used in identity design. They have some nice, thick strokes, but they also have very thin strokes that tend to disappear, especially when the type is reversed.
Of all the Seven Deadly Sins, using elements too small or lines too thin is perhaps the most common, second only to designing a logo that fails to work in solid black.
The “too small, too thin” sin is one of the few ever committed by great identity designers such as Paul Rand, Saul Bass or Chermayeff Geismar and Haviv. In virtually every case where they used tiny elements or thin lines, the identities have been replaced or amended. Over the years, countless designers for many companies have produced logos with lines that are too thin for good, solid reproduction. Most of these companies have redesigned their logos to correct this. Rand and Bass even corrected this mistake in their own logos, IBM and AT&T respectively. They realized that you can’t fight thin lines; you just have to get rid of them.
Some designers try to hide from this reality by specifying that their identity ought not be used below a certain size. Unfortunately, many times identities must be used smaller than the “allowable” minimum. Companies often work with other companies where the identities of all participants will be shown in a “logo soup.” The costs of newspaper ads and Yellow Pages ads often encourage the use of smaller identities. But the coarser paper used in both of these further aggravates the effects of tiny elements and thin lines.
A variation on this problem happens when any line tapers gradually to a fine point. Whenever these lines are reversed, ink fill-in will cut off the tip of the point. This may be why Facebook Messenger’s icon has recently changed to have the two lines end with rounded points.
Adapted from Logo Design Theory: How Branding Design Really Works