By Patsy Isenberg Key figures from Flint Fit, a project to turn 90,000 water bottles into fashion, were on hand at The Capitol Theatre Sept. 15 to show Flint what became of the truckload of plastic collected in the city last fall. The clothes, created by a triumvirate of artists in New York City; thread and material manufacturers in Greensboro, North Carolina; and Flint-based sewers at the St. Luke N.E.W. Life Center aren’t available to the public yet.  But the high-fashion prototypes — appropriately in water-based items like rainwear, swimsuits and hats–suggested a positive...