You can blame the VOC regulations for orange peel for the most part, because today's paints are high solid, low solvent as opposed to lacquers and early enamels that were high solvent, low solid. The latter flows out and self levels to a certain extent, as it cures, with the help of the high solvent content.
Today's urethanes are lacking in solvents to help it flow out and level, and the paint cures with the orange peel effect more pronounced.
Today's urethanes are lacking in solvents to help it flow out and level, and the paint cures with the orange peel effect more pronounced.