Formable reflective multilayer body

Claim 1

A formable polymeric multilayer reflective body having a substantially uniform reflective appearance over substantially the entire range of the visible spectrum comprising: at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 40% of visible light incident on said body is reflected, a substantial majority of the individual layers of said body having optical thicknesses in the range where the sum of the optical thicknesses in a repeating unit of said polymeric materials is between about 190 nm and 1700 nm, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03, wherein said layers have a gradient of optical layer repeat unit thicknesses through the thickness of said body which is sufficient to reflect substantially the entire range of visible light up to a predetermined maximum draw ratio ##EQU8## where MDR is the maximum draw ratio; t i is the initial thickness of the optically active layers in the multilayer stack; t f is the final thickness of the layers in the microlayer core in the thermoformed part at MDR; (λ 1 ) max is the maximum reflecting wavelength in the body in nanometers; the summation from i=1 to j of (N i d i ) max is the maximum optical repeat unit thickness in the body in nanometers; N i is the refractive index of the i th layer in the repeat unit; d i is the physical layer thickness of the i th layer in the repeat unit; and the constant 680 nm is the upper wavelength limit of visible light.