When the kite is in the region that it is behaving like an airfoil then wing efficiency dominates. Try and keep this in mind as the discussion continues. Some Terms Aspect Ratio . In the simplest terms this is the wing span divided by the chord. This applies only for rectangular wings.
Aspect ratio is, for more complex shapes the wing span squared divided by the wing area.
For delta shaped stunt kites you get a larger wing span by increasing the nose angle, this also has the effect of decreasing the wing area. Both contribute to a higher aspect ratio. On the other hand the higher aspect ratio will reduce tip vortex drag and make the wing more efficient when it is in the airfoil region of flight. Wing Loading . Wing loading is the weight of the kite divided by the area.