Pop's bass rosin is popular worldwide because it has unique qualities that enable the bow to really "grab" the string and make a very pleasing sound. Players report that it takes only a small amount of Pops' rosin on the bow -- only two or three swipes for every few hours of playing.
The rosin is necessarily soft to produce the qualities that give the bow such a good "grab." The label reminds one to keep it upright and in the red container. If stored on its side, it will "run," particularly in hot weather and begin to look mis-shapened.