A headgear for use with a respiratory mask, comprising: a back panel having a trapezoidal shape comprising a top edge, a bottom edge and lateral edges that connect the top edge to the bottom edge, the back panel formed from two layers of 3D fabric folded from a sheet of 3D fabric to have a folded edge, the folded edge forming the bottom edge of the back panel, having a first width W 1, which extends across the back of a user's neck in use, a sewn edge forming the top edge of the back panel, having a second width W 2, the first width W 1 being less than the second width W 2, the sewn edge having a seam allowance having free ends extending radially inwardly within the interior of the back panel, the lateral edges of the back panel being linear towards the folded edge and convex towards the sewn edge, the distance between the lateral edges of the convex region defining a third width W 3, which is the widest point of the back panel, and the corners of the free ends of the seam allowance defining a fourth width W 4, the fourth width W 4 being less than the third width W 3 such that the seam allowance does not extend beyond the lateral edges of the back panel; and perimeter portions, formed from a foam laminate material, stitched to the respective lateral edges of the back panel along a join. a back panel having a trapezoidal shape comprising a top edge, a bottom edge and lateral edges that connect the top edge to the bottom edge, the back panel formed from two layers of 3D fabric folded from a sheet of 3D fabric to have a folded edge, the folded edge forming the bottom edge of the back panel, having a first width W 1, which extends across the back of a user's neck in use, a sewn edge forming the top edge of the back panel, having a second width W 2, the first width W 1 being less than the second width W 2, the sewn edge having a seam allowance having free ends extending radially inwardly within the interior of the back panel, the lateral edges of the back panel being linear towards the folded edge and convex towards the sewn edge, the distance between the lateral edges of the convex region defining a third width W 3, which is the widest point of the back panel, and the corners of the free ends of the seam allowance defining a fourth width W 4, the fourth width W 4 being less than the third width W 3 such that the seam allowance does not extend beyond the lateral edges of the back panel; and the back panel formed from two layers of 3D fabric folded from a sheet of 3D fabric to have a folded edge, the folded edge forming the bottom edge of the back panel, having a first width W 1, which extends across the back of a user's neck in use, a sewn edge forming the top edge of the back panel, having a second width W 2, the first width W 1 being less than the second width W 2, the sewn edge having a seam allowance having free ends extending radially inwardly within the interior of the back panel, the lateral edges of the back panel being linear towards the folded edge and convex towards the sewn edge, the distance between the lateral edges of the convex region defining a third width W 3, which is the widest point of the back panel, and the corners of the free ends of the seam allowance defining a fourth width W 4, the fourth width W 4 being less than the third width W 3 such that the seam allowance does not extend beyond the lateral edges of the back panel; and the distance between the lateral edges of the convex region defining a third width W 3, which is the widest point of the back panel, and the corners of the free ends of the seam allowance defining a fourth width W 4, the fourth width W 4 being less than the third width W 3 such that the seam allowance does not extend beyond the lateral edges of the back panel; and perimeter portions, formed from a foam laminate material, stitched to the respective lateral edges of the back panel along a join.