What role does the square pattern on the surface of the sake glass serve?

The square pattern wrapped around the surface of Toyo Sasaki's sake glass goes beyond simple decoration.

It serves as scale marks. Using the square sections on the exterior as a reference, you can pour liquor in a consistent ratio without taking out a separate measuring tool^[2]. This means you can gauge the amount according to the squares instead of guessing by eye, without the hassle of preparing a cocktail jigger or measuring cup.

This glass is used as a multipurpose glass for holding various alcoholic drinks, such as whiskey, beer, and wine, in addition to sake^[3]. Within its 200ml capacity, it is convenient to create your own blend by gauging the amount of the desired liquor and mixer using the square pattern^[4].

hmmm, while it looks like a neat pattern on the outside, it serves as an honest guideline that preserves the ratio of flavor when actually filling it with drinks.