I found mine in the Halloween section at Michael’s craft store. However, they are sold abundantly online. The graduated cylinders found at Michael’s are great for drinkware but remember, they are for show! Don’t depend on the measurements on the sides. They are likely incorrect! If you can’t find u003ca href=u0022https://amzn.to/3q9qQbiu0022 target=u0022_blanku0022 rel=u0022noreferrer noopener sponsored nofollowu0022u003egraduated cylindersu003c/au003e near you, and would prefer not to shop online, a 3-ounce double shot glass will work, in a pinch. However, the color gradation will be less noticeable. If making these for a party, I highly recommend using some u003ca href=u0022https://amzn.to/3CM7u3Lu0022 target=u0022_blanku0022 rel=u0022noreferrer noopener sponsored nofollowu0022u003echeap plastic test tubesu003c/au003e!