How can a reversible isobaric process be done on a gas?

I know that a reversible isothermal process is done on a gas by maintaining equilibrium throughout the process under an isothermal condition. That is,change the volume of the gas through PV-work by some infinitesimal amount dV then wait for the gas to be in equilibrium with its environment(which will take a looooong time, theoretically) and then just repeat the process until the end. But how can I visualize a reversible isobaric process? Is it even possible?