A patient interface for sealed delivery of a flow of air at a continuously positive pressure with respect to ambient air pressure to an entrance to the patient's airways including at least entrance of a patient's nares to ameliorate sleep disordered breathing may include a seal-forming structure comprising a foam undercushion and a textile membrane for contact with the patient's face; a positioning and stabilising structure to maintain the seal-forming structure in sealing contact with an area surrounding an entrance to the patient's airways while maintaining a therapeutic pressure at the entrance to the patient's airways; and a plenum chamber pressurised at a pressure above ambient pressure in use.