4. 2 Typography Serif: scale The type sizes in the system are derived from a mathematical formula which systematizes traditional types sizes. It utilizes a pentatonic scale. This means the type size doubles every five steps. 
 Pentatonic Formula: a n = a 0 × r (n-1) a n = The type size / term in the sequence a 0 = The base type size, 12pt r = 2 (1/5) n = The step in the scale. e.g. step 1 = 12pt Style Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light Signifier Light 9 10 11 12 14 16 18 21 24 28 32 36 42 48 55 64 73 84 96 140% 140% 140% 140% 140% 140% 140% 140% 130% 130% 130% 130% 130% 120% 120% 110% 110% 110% 110% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% -1% (-0.01em) -1% (-0.01em) -1% (-0.01em) -1% (-0.01em) -1% (-0.01em) -2% (-0.02em) -2% (-0.02em) -2% (-0.02em) -2% (-0.02em) metric metric metric metric metric metric metric metric metric metric metric metric metric metric metric metric metric metric metric Type size Line -height Letter-spacing Kern setting