The invention relates to a patient interface for sealed delivery of a flow of air at positive pressure. The patient interface comprises a plenum chamber (3200) at least partially forming a breathing chamber pressurisable to a therapeutic pressure above ambient air pressure. The plenum chamber includes a plenum chamber inlet sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient and a seal-forming structure constructed and arranged to form a seal with a region of the patient's face surrounding an entrance to the patient's airways. The seal-forming structure has an opening formed therein to deliver the flow of air to an entrance to the patient's nares. The plenum chamber (3200) comprises a textile outer layer (3210), a textile inner layer (3212) and a foam interior (3211) disposed therebetween. The textile outer layer and the textile inner layer are respectively joined to opposing sides of the foam interior.