Abstract: A composite of selectively removable layers of silk screen printing ink above a base layer serving as a substrate or receptor surface. The silk screen printing inks have compositions allowing them to be permanent, selectively removed with water and selectively removed with water and detergent as a washing compound. The composite is used for selectively altering the graphic or artistic presentation of a sales or promotional item so as to reveal a hidden message underneath or simply to alter or eliminate all or portions of the presentation.

Abstract: Injectors are disclosed for use in an underoxidized burner having a single or double stage internal combustion chamber for receiving gaseous or liquid fuel such as diesel for mixture with air or oxygen and subsequent ignition by a spark plug. The injector includes feed conduits or tubes for simultaneously conducting air and fuel to a mixing device having a baffle arrangement against which separately injected air and fuel impinge causing a complete air/fuel blending which is ignited, burned and exhausted. The injector may accept effluent gases for mixing with water to produce maximum hydrogen H.sub.2 from fuels. A lamina flow is produced which is folded over and reversed in direction within the combustion chamber.