(A) contacting a first film with a second film; and

(B) heating selected portions of at least one of the first film and second film to a temperature at or above a fusion temperature, so that the first film is heat sealed to the second film at selected areas, the selected areas providing a heat seal pattern that provides inflatable chambers between the first film and the second film, the heating being carried out by bringing the first film and second film into overlying contact with each other with the first film contacting the outer surface of a heated sealing roller and such that at least the first film makes a partial wrap around the outer surface of the sealing roller, the outer surface comprising a first surface portion comprising a first material having a first thermal conductivity and a second surface portion formed of a second material having a second thermal conductivity lower than the first thermal conductivity, the first and second surface portions being substantially flush with each other at the outer surface and the first film contacting the first and second surface portions such that only areas of the first film in contact with the first surface portion are heat sealed to the second film while unsealed areas of the films remain where the first film contacts the second surface portion, the second surface portion preventing tenting of the films in the unsealed areas.