Second:

Single greatest Flite-Metal attribute over aluminum gutter tape or air conditioning tape is its capacity to stretch greater than 20% of its surface area. Stretch of a 12" by 12" piece of Flite-Metal can exceed 20% if it is not applied per our instructions. Work from the center and right angle to largest contact patch line outward to panel perimeter of 1/2 a panel at a time.

Some customers have reported applying 12" widths by peeling the backing off a single edge then slowly applying Flite-Metal to the surface "across the area" of the panel. This will work sometimes, but more often than not, it does not permit working a compound curve because the area mass is not being applied proportionally out to the perimeter of the panel.

A parity to the application of Flite-Metal is found in covering with plastic covering films where the adhesive is heat activated with an iron. If you have ever covered with plastic film...you must deal with the accumulative stretch of the heat activated film caused by the surface contact patch being the size of the iron. Over time, you must learn to pre-heat ahead of the contract patch to prevent plastic film cupping under unheated portion of  film. Is this an simple example of accumulative stretch?