July 26, 2008 - The film immediately cut down on glare and solar gain, and reduced UV rays by about 99 percent, he says. The Beatons chose a slate-colored tint. Low-E, or lowemittance glass, is among the newest generation of energyefficient windows. These films come with floral, aquatic, cloudscape, or geometric designs, or they can mimic frosted, etched or stained glass.