Glyph design: O-derived letters ( C G Q )

s
o
z
i
v

S
I
V

O
Z
H J
U
X W A Y

G Q
C
E F L T
M

D P
K
N

B
R

From the ‘O’ comes the ‘C’, ‘G’, and ‘Q’. The capital ‘C’ and ‘O’ differ from their lowercase counterparts in that their bowls are virtually identical, while the ‘c’ and ‘o’ have marked differences in curvature and stress. The ‘C’ is produced by taking half an ‘O’ and extending the ends to meet up with beak serifs from the ‘Z’. The bowl is extended to meet those serifs, which depresses the upper and lower left corners of the letter slightly (marked with pink arrows).

It is very common to leave the ‘C’ like that, with two serifs on both ends of its bowl. A minority of typefaces (such as Le Monde Journal) however remove the bottom serif, tapering out the bowl into a finial.

The ‘G’ is almost exactly a capital ‘C’ with a chin (the straight part) made from the top of a capital ‘I’. The chin typically reaches up to about the level of the crossbar on the lowercase ‘e’, sometimes a bit higher. It’s very common for the spur of the ‘G’ to be lowered slightly, like with the lowercase ‘b’. The barb (the bilateral serif on top of the chin) is usually skewed towards the interior of the letter, with the shorter side pointing out and the longer end pointing in. The ‘G’ is generally slightly wider than the ‘C’, and the right edge of the chin often aligns with the edge of the beak serif.

The bowl of the ‘Q’ is exactly like the ‘O’. The tail can take on many diverse forms and there’s a great deal of artistic freedom in the design of this part of the letter.

Top left to right: Garamond, Sabon, Minion, Warnock, Book Antiqua, Le Monde Journal, Century Schoolbook, Linux Libertine, Proforma, Droid Serif, Liberation Serif, Bodoni, New Caledonia, FB Vogue Didot.

As a rare case of when you’re allowed to do this in type design, you can just stick the tail onto the ‘O’ with no modification to the bowl.