How to make a cartoon arm:
I’ll demonstrate an arm in Anime Studio, but it’s the same for Creatoon, Toon Boom, or any other program. The only difference may be how you rig it.
Here’s what the cartoon arm looks like when it’s assembled:
To make the arm versatile, it should be made from 3 pieces; a hand, forearm, and upper arm. The upper arm and forearm should be symetrical shapes. This allows the arm to change direction without having to make a switch layer for the different pieces.
The arm is able to change direction easily, just by switching the hand. One the arm breaks the plane of what’s natural, we change the hand layer make the forearm and upper arm look correct. See the examples below: