Shabbos 1:4

The following are among the laws that were decided in the upper chamber of Chananiah ben Chizkiya ben Gurion. On that day, the representatives of Beis Shammai outvoted those of Beis Hillel and eighteen matters were settled.

Shabbos 1:5

Beis Shammai say that one may not start to soak ink, dye or cattle feed in water on Friday unless there is enough time for them to dissolve before Shabbos; Beis Hillel permit it.