Abstract: A decorative, light transmitting panel including opposite inner and outer faces is formed on a substrate comprising injection molded clear plastic resin having a low level of process induced internal stress and at least one optical quality surface finish underlying the outer panel surface for optimizing light transmission through the resin. A thin, hard, transparent, abrasion and chemical resistant and ultraviolet light resistant protective layer or coating of plastic resin is permanently bonded to the optical quality surface finish of the low stress substrate to form at least one outer surface of the whole panel and the coating provides a hard, tough abrasion resistant outer surface capable of lasting a long time without substantial diminishment of light transmission through the panel. The low internal stress of the molded resin substrate provides superior adhesion for permanently bonding the hard protective coating to prevent micro-cracking and/or delamination during normal thermal cycling between - 40.

Abstract: An architectural building block is formed of light transmitting, molded plastic material to resemble a common glass block or brick and comprises a plurality of hollow half members joined together along a seam to form a hollow block enclosure with the seam spaced intermediately between a pair of opposite planar outer side faces of the block. Each half member has an inner surface and an outer surface comprising one of the outer side faces of the block integrally joined around its periphery to an inwardly directed peripheral edge flange having a free edge providing one joining edge of the seam. At least one of the outer opposite side faces of the block is provided with a thin, hard, transparent, abrasion, chemical and ultraviolet light resistant protective coating of plastic resin permanently bonded to an outer side face of the block to provide protection from the environment and weather.

Abstract: An architectural building block is formed of light transmitting, molded plastic material to resemble a common glass block or brick and comprises a pair of halves joined together along a seam to form a hollow block with the seam spaced intermediately between a pair of opposite planar outer side walls of the block. Each half has an inner surface and an outer surface comprising one of the outer side walls of the block integrally joined around its periphery to an inwardly directed peripheral edge wall having a plurality of planar wall segments and having a continuous free edge providing one joining edge of the seam. Integrally formed snap lock connectors are provided adjacent each corner of the block for interconnecting an adjacent block laid up in a wall structure and a flange structure is formed along each wall segment between the connectors providing a surface for backing up joint adhesive applied between adjacent wall segments of laid up blocks.