They consist of two interlaced materials that havedifferent optical properties in particular, different refractive indices, a measure of how much a substance bends light.
At TWB Co. a single laser welds steel sheets of differentproperties into a single raw sheet that Cadillac can have stamped into a door panel without any of its own welds.
You'll also get a chance to visit differentproperties to see if they meet your standards, as not all have modern conveniences such as air conditioning and high-speed Internet access.