Family Stem Weights Calculator Version 4.0

Thin

Black

Steps

Decimals?

 

Equal Steps

 
 
 
 
 
 
 
 
 
 

Impallari Formula

 
 
 
 
 
 
 
 
 
 

Luc(as) Formula

 
 
 
 
 
 
 
 
 

 

Styles

 

Equal Steps

 

Impallari Formula

 

Luc(as) Formula

Step 1

 

20

 

20

 

20

Step 2

 

+25 45

 

+9 29

 

+7 27

Step 3

 

+25 70

 

+16 45

 

+9 36

Step 4

 

+25 95

 

+21 66

 

+13 49

Step 5

 

+25 120

 

+27 93

 

+17 66

Step 6

 

+25 145

 

+31 124

 

+24 90

Step 7

 

+25 170

 

+34 158

 

+31 121

Step 8

 

+25 195

 

+33 191

 

+42 163

Step 9

 

+25 220

 

+29 220

 

+57 220

 

My formula describes an Ogee Curve in between the Lucas Theory and Equal steps.
This seems to be the most useful pattern to distribute weight across a font family.
Especially in large families with many weights, or where the Black-Thin difference is lengthy.

You can take this values as a pretty good starting point, and then refine acording to your eyes.
Cheers, Pablo Impallari.

 

Reference:
Luc(as) de Groot’s Interpolation Theory
Weight interpolation and maths
Golden Section as a method for finding regular and bold complements
Using Multiple Masters to Generate Weights in a Family - Insight?
Font weights and font weight scaling
CSS Fonts Module Level 3 - font-weight property

 

Discuss, suggest changes and improvements:
Project Page, Typophile and TypeDrawers

 

More Impallari Tools:
Drag and Drop Font Testing page
Simplepolator
Spacing Macro