Patient interface having seal-forming structure with varying construction

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 a patient's airways including at least entrance of a patient's nares, wherein the patient interface is configured to maintain a therapy pressure in a range of about 4 cmH2O to about 30 cmH2O above ambient air pressure in use, throughout a patient's respiratory cycle, while the patient is sleeping, to ameliorate sleep disordered breathing;

• said patient interface comprising:
• a plenum chamber at least partially forming a cavity pressurisable to a therapeutic pressure of at least 6 cmH2O above ambient air pressure, said plenum chamber including a plenum chamber inlet port sized and structured to receive a flow of air at the therapeutic pressure for breathing by a patient;
• and
• a seal-forming structure having a textile membrane constructed and arranged to form a pressure-assisted seal with a region of the patient's face surrounding an entrance to the patient's airways inferior to a nasal bridge region of the patient's face, said textile membrane having a hole formed therein such that the flow of air at said therapeutic pressure is delivered to at least an entrance to the patient's nares, the seal-forming structure constructed and arranged to maintain said therapeutic pressure in the cavity throughout the patient's respiratory cycle in use,
• wherein the seal-forming structure includes a flexible support structure attached to and supporting the textile membrane, and
• wherein the textile membrane comprises a textile material and an air impermeable layer applied directly to the textile material to make the textile material air impermeable, the air impermeable layer having a first thickness at a first location on the textile membrane and a second thickness at a second location on the textile membrane that is different than the first thickness.