In order to obtain the rheological and fluent parameter of filling techniques as designing basis, the filling paste round-pipe-test is a necessary work.

In the south, the favorite traditional filling is lotus seed paste, while northerners like everything from red bean and date paste to ham and nuts.

The seasonal round cakes traditionally have a sweet filling of lotus seed paste or red bean paste and often have one or more salted duck eggs in the center to represent the moon.