Abstract: A directional image is created in transparent sheeting comprising a monolayer of microlenses by forming deformations in at least some of the microlenses by irradiation with a laser beam which has a short pulse duration. The directional images may be formed in transparent sheeting which has been applied to a document as an overlay. When viewed under diffuse lighting conditions, the deformations appear as a dark image. The deformations may be formed so that when viewed under retroreflective conditions within a conical field the image is darker than the surrounding background, and when viewed under retroreflective conditions outside the conical field the image is brighter than the surrounding background.

Abstract: A directional image is created in substantially transparent retroreflective sheeting comprising a monolayer of microlenses and a partially light transmissive mirror disposed at the rear surfaces of at least some of said microlenses. The image is created by irradiation of the sheeting with a laser beam to form axial markings associated with at least some of the microlenses. The image may be formed in sheeting which has been applied to a document as an overlay.

Abstract: Sheeting having images that are viewable within limited angles of viewing from the front of the sheeting are prepared from retroreflective sheeting or from sheeting patterned after retroreflective sheeting, i.e., sheeting having a monolayer of microlenses like the monolayer of microspheres in retroreflective sheeting. A layer of transparent material covers the back surface of the microlenses. Axial markings are disposed behind individual microlenses at the back of the layer of transparent material and the markings are viewable from the front of the sheeting as an image.

Abstract: An implant for use in a human body having an integral attachment surface adapted to permit tissue ingrowth. The attachment surface has an inner attachment surface and a multiplicity of spaced posts projecting from the inner attachment surface. The posts each have side attachment surfaces which are generally cylindrically concave, intersect to define post edges, and are radiused at their intersections with the inner attachment surface. A method of forming the attachment surface on an implant with a laser is also included.