I didn't want to be wasteful and start off by testing out the feasibility of my design on acrylic, the final product material, so I created a cardboard model after measuring the desired size of each individual piece. The bottom piece was made through a process of trial and error that would result in the perfect circle that had the same circumference as the top of the beer can. The shoulder piece was made involving slightly more math, but the bottom circle's circumference had to match that of the bottom piece's, while the top circle had to be wide enough for the top piece to fit through. And finally, the neck piece was just another simple cylindrical shape that could fit snuggly into the shoulder piece. The measurements had to be precise; otherwise, when putting them together, the final product would spill beer everywhere.