Wide-area solid-state illumination devices and systems employing a light guide formed by a sheet of an optically transmissive material and selectively patterned in designated areas. Printed light extraction features are used to form a plurality of patterned areas are separated from each other and from edges of the light guide by separation areas which are generally free from the light extraction features. One or more light emitting diodes (LEDs) is optically coupled to the light guide and provides a light source. The light guide is sandwiched between a front sheet and a reflective back sheet. The front sheet includes opaque areas and a plurality of optically transmissive areas disposed in registration with the patterned areas.