Link to the project: EiMIM X, Y, and Z Pens
I messed up and said the wrong pen type in my video:
X pen is the small pen (mini G2), Y is the medium pen (Parker), and Z is the long pen (regular G2).
Link to new Tactile Turn project: Mover and Shaker
Shop where you can buy X, Y, and Z Pens
Article on 6061 and 7075 aluminum.