A plurality of microstructures is provided, with each microstructure having at least a first side and at least a second side terminating at a peak. At least some of the peaks can include an elevated portion to space the peaks away from adjacent optical sheets, surfaces, films, substrates, or other layers...http://www.google.ca/patents/US7330315?utm_source=gb-gplus-sharePatent US7330315 - Light-redirecting optical structures
