I really wasn't sure how big to make the volleyball.

I looked up how big volleyballs were, but that wasn't the issue. Scale in comics with stylized characters gets weird, as everything is relative.

An accurately sized volleyball might not look too small relative to the character's body, but what about when compared to the cartoonishly-proportioned head and hands?

And what about characters of varying designs? Within one style, characters can be stylized in different directions in order to emphasize character traits. Given this lack of consistency, what do you size the ball relative to? Do you even keep it one size, or do you cheat it depending on who or what is in the scene?

Ultimately, it's a judgement call. In this case, I decided this guy is naturally big, so the ball looking small was fine. With Grace, hitting it, maybe I'll cheat its size larger than what would be technically correct to highlight the difference. That's a stylistic choice I'll have to make.

Anyway, if the volleyball looks like a beach ball in the next comic, now you'll know why.