Optical Weighting
Optical Weighting
What you perceive and what is there are not always the same thing.
The ancient Greeks made imperceptible optical adjustments to their architecture so it would appear as intended. Type designers do the same thing—optically adjusting shapes for an intended effect.
Vertical vs Horizontal weight
Our brains perceive horizontal and vertical weight differently.
Vertical weight is perceived to be heavier than horizontal weight. The shapes on the right are constructed from equal line weights, so the horizontals appear extra heavy. If you want to sound real fancy you can call it “anisotropic contrast.”
Diagonal shapes fall somewhere in between the two, depending on the angle.
Converging shapes
Shapes in close proximity can skew our perception of weight even further.
Converging lines appear to be heavier at their intersection, and stacked shapes tend to feel heavier as well. The crossbar of the H feels a bit heavy, but nothing compared to the comical arms of the E.
Here’s what an improved
version looks like:
Equal weight
Optically Optimized
Weight tapering
When it comes to converging lines, the solution is weight tapering. Below are three different methods.
No method is necessarily better than the others, but some might perform better in different contexts. Though rather obvious, curved tapers work really well when the converging lines are also curved.
Straight Taper
Curved Taper
Notched Taper
Optical sizing
The effects can be even more dramatic at smaller sizes.
The third option appears out of balance at larger sizes, but appears to be the most balanced at smaller sizes. This isn’t to be confused with ink traps, though the concepts are similar. Ink traps were designed to counteract ink bleeding into corners, which has to do with how the production impacts optics, not optics alone.
Default
Tapered
More tapered
Here are a few practical examples:
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
Equal weight
Optically Optimized
The solution
Here are some rules of thumb.
9:10 Ratio
For vertical-horizontal measurements a 9:10 ratio works pretty well as a rule of thumb. On heavier weights, that ratio can be more like 8.6:10, and on lighter weights the ratio can be more like 9.2:10, but it tends to be situational and a judgement call.
9.5:10 Ratio
Weight tapering aside, for vertical-angled measurements the ratio should depend on the angle. 45° angles split the difference between vertical and horizontal measurements. 22.5° would be 9.75:10, and 67.5° would be 9.25:10.
Weight tapering
If you’re designing something small, consider making the tapering more dramatic—somewhere between 50–100% more than normal tapering.
Parting thoughts
Consider applications
Before you go changing horizontal/vertical proportions, consider if it’ll ever be viewed at an angle (eg: a circular logo rotated 30°)? If you optically correct the shape, then rotate it, you’ll make the optical illusion worse in those instances.
Along those lines, if what you’re designing will be viewed at small sizes, consider making an alternate version for small sizes with more dramatic tapering.
For better or worse, it’s all contextual
The joy and curse of this stuff is that you’ll always find new situations to navigate. Sometimes you can’t or shouldn’t do anything to optimize optics, and other times you’ll have to do a lot. At the end of the day it’s all a judgment call and experience plays a big role.