Examples of a container assembly are disclosed herein. An example of the container assembly includes a regulated tank to supply printing composition and a free tank to supply reserve printing composition to the regulated tank. The container assembly also includes a regulator assembly to control flow of the reserve printing composition from the free tank to the regulated tank and an inflation assembly to prime the regulated tank to supply the printing composition. The container assembly additionally includes a labyrinth to fluidically isolate the flow of ambient air into and out of the regulator assembly from the flow of a supply of air into the inflation assembly.