Patent ID: 7655104

Claim:
A method of forming a moisture resistant flexible film for covering an architectural structure comprising the steps of: laminating a first oriented plastic layer and a second oriented plastic layer to one another where the orientations of the first and second layers cross at an angle between, but not equal to, zero degrees and 180 degrees relative to one another to form a flexible membrane defining a plane; forming in the flexible membrane a first plurality of spaced apart, discrete embossings extending outwardly of the plane, the embossings formed in rows in an x-direction and in columns in a y-direction, the rows being spaced from one another and the columns being spaced from one another, the embossings configured to facilitate moisture drainage; and perforating the flexible membrane to enable water vapor permeation and to preclude liquid water permeation, wherein in the forming step the first plurality of spaced apart discrete embossings are formed transverse to the plane in a first direction and a second plurality of spaced apart, discrete embossings are formed in the membrane extending outwardly of the plane in a second direction opposite of the first direction, the embossings formed in rows in an x-direction and in columns in a y-direction, the rows and columns of the first plurality of embossings being spaced from one another by rows and columns of the second plurality of embossings.