Kolstein's exacting research and development has brought us their Ultra Formulation Supreme rosin. Well-known for its low powdering and smooth, easy bowing. Now all Kolstein Ultra Rosin is encased in a special silicone "wrap" which keeps the rosin fresh longer - which is, in turn, inside a cardboard storage container with lid.
We have All Weather/Regular, Soft, and Hard formulations available, so you can tailor your choice to your preference and/or climate.
Rosin is key in getting a good bowed sound, so don't cheap out on this key ingredient to success, it can last a long time - and isn't very expensive. In fact, some bassists carry two or three different cakes just in case the environment makes another consistency better for that particular situation. When the humidity is high, the more powdery, harder rosin is usually best, and during very dry periods some stickier stuff may be needed.
New players: I include my tip sheet covering the care and usage of rosin.