3M Process Color Series 990 is transparent (except for 990-05 black which is opaque), screen printable, and quick-drying. Colors are weather resistant, have excellent color retention, and do not require clear coating. They are recommended and intended for use on 3M Engineer Grade Series 3200 and Series CW80 Reflective Sheetings. Application to other grades or types of reflective sheeting or substrates is not recommended and may result in premature product failure after outdoor exposure. Series 990 process colors result in evaporation of more solvent in less time than slower drying inks; therefore, when they are dried in large volumes, sufficient ventilation and exhaust should be provided. Series 990 process colors are intended for use as a matched component in the production of traffic control signs. Signs made of these materials will have a similar appearance viewed from a vehicle either in the daylight or at night.