As with fragmentation, the technique of rendering the whole identity with lines alone risks making the lines or spaces too delicate for clarity in small sizes or viewed from a distance. Drawing lines that are too lightweight for the overall size will make the whole logo too insubstantial (Deadly Sin of Logo Design #2: Lack of Mass). If lines are close together, it is safest to make lines and gaps the same thickness.
Because sooner or later, gaps become positive lines and line become gaps when the identity is reversed.
The samples shown here have decent mass. When designing with this technique, a good test is to print a design at no bigger than one-half inch on plain paper. If it is indistinct or begins to blur or fill in, either the rendering needs to be simplified or the lines (or gaps between) need increased weight.
A good rule of thumb is: make all lines either of uniform thickness or of variable thickness. Don’t mix techniques (remember: coincide or contrast). Tools like Adobe Illustrator are particularly good at keeping strokes exactly the same and separating one stroke from another at exact distances. Line end caps and corners can be blunt, mitered or round.
We now can make vector strokes thicker or thinner. Here again, strive for the beauty and grace of simplicity. Bezier curved lines are inherently more graceful when the fewest possible anchor points are used. The same is true of making lines thick and thin: the fewest changes will give the most graceful lines. Even lines that just taper at the ends and are mostly of uniform thickness can be effective.
Another consideration is how lines join at corners. If they join with sharp points, that can accentuate the curvilinear quality of the line. Ironically, lines joined in rounded corners will just look blobby and will not produce as curvaceous an effect.
Adapted from Logo Design Theory: How Branding Design Really Works