billowing inflated skin 79 the anchor ties 86 87 merely act as restraints along intermediate points of the film holding such intermediate protions in spaced fashion from the skin to thereby define a plurality of parallelapiped shaped dead air spaces 95 between the films 81 83 and spaces 96 between the film 81 and skin 79 fig6 illustrates an embodiment which achieves the objectives of the present invention without the use of distinct anchor tie elements in this embodiment the middle film 181 is secured to the anchor strips 185 along lines 182 and is heat sealed to the outer skin 179 along the line 189 the inner film 183 is secured to the anchor strips 185 along lines 184 and is heat sealed to the middle film along lines 193 in much the same manner as previously as the positive air pressure inflates the air structure the skin 179 billows outwardly from the restraining shroud lines 159 161 and extends the middle and inner films in the relatively taut fashion shown in this case air spaces of triangular cross section 196 are created between the skin 179 and the middle film 181 while similarly shaped air spaces 195 are created between the middle and inner films while the present invention has been particularly set forth in terms of specific embodiments thereof it will be understood in view of the present disclosure that numerous variations upon the invention are now enabled to those skilled in the art which variations in propriety yet reside within the scope of the.