Abstract: Pigment flakes are provided which can be used to produce colorant compositions having color shifting properties. The pigment flakes can have a symmetrical coating structure on opposing sides of a reflector layer, can have an asymmetrical coating structure with all of the layers on one side of the reflector layer, or can be formed with encapsulating coatings around a reflector layer. The coating structure includes a selective absorbing layer on one or more sides of the reflector layer, a dielectric layer on the selective absorbing layer, and an absorber layer on the dielectric layer. The pigment flakes exhibit a discrete color shift such that the pigment flakes have a first color at a first angle of incident light or viewing and a second color different from the first color at a second angle of incident light or viewing. The pigment flakes can be interspersed into liquid media such as paints or inks for subsequent application to objects or papers.

Abstract: A surgical knife which provides improved multi-sided incisions and is preferably allows for a substantially cruciate, or cross-shaped incision. The surgical knife includes a handle and a multi-bladed portion located at one end of the handle. The handle is sized and configured to maximize grip and surgical manipulation thereof. The multi-bladed portion is formed from a primary blade and a secondary blade. The primary blade is configured with two exemplary primary blade members. The primary blade members are formed with sharpened edges which combined to form a sharpened distal point of the primary blade. The secondary blade is formed with sharpened edges and cooperates with the primary blade. The coupling of the primary blade and the secondary blade is such that the distal end of the secondary blade is located at a distance from the sharpened distal point of the primary blade.