The surface of an article, such as a glass envelope for an electric lamp, is provided with a decorative pattern or indicia by coating the article with a vitreous material that includes a substance (such as lead oxide) that undergoes a permanent change in color when heated under reducing conditions, subjecting the article to a laser beam and a reducing gas flame, and varying the position of the article relative to the beam at a speed and in a manner such that the beam scans the article and thereby melts preselected portions of the vitreous coating and changes the color of such portions. In the case of a vitreous or ceramic article that is susceptible to thermally-induced fracturing, the vitreous coating material is preferably deposited on the article in the form of a frit and the article is preheated to a temperature which is near or above its strain point, thus fusing the frit in place just before the glazed heated article is exposed to the reducing environment and laser beam. An apparatus and method for concurrently firing a glass frit on an article and color-etching the resulting glazed article with a laser having control means which includes a prototype article are also disclosed.