| 主权项 |
1. A sheet having front and back major surfaces and comprising a first array of a plurality of polymeric ribbons and a plurality of polymeric strands, the plurality of polymeric ribbons comprising first polymeric ribbons and the plurality of polymeric strands comprising first polymeric strands, wherein:
(1) each of the polymeric ribbons and polymeric strands is of elongate form having a longitudinal axis, has two opposing sides, two opposing ends, and two opposing edges, and has a width, length, and thickness; (2) each of the polymeric ribbons has a thickness-to-width aspect ratio, typically of at least three-to-one, and at least one side that is substantially continuously bonded to a polymeric strand, and a thickness greater than the thickness of the polymeric strands; (3) the longitudinal axes of the polymeric ribbons and polymeric strands are substantially parallel, the polymeric ribbons and polymeric strands are arranged in the array such that the first edges of the first polymeric ribbons are oriented in common direction from the polymeric strands so as to define the front major surface of the sheet; and (4) the polymeric ribbons and polymeric strands have adjacent segments that have a perceptibly different optical appearance, such that the first array exhibits a first optical appearance at a first orientation and a second optical appearance at a second orientation, the first optical appearance being perceptibly distinct from the second optical appearance. |
