The paper gives the status of a 5-year EPA research program on spray painting transfer efficiency. The objective of the program has been to develop a laboratory transfer efficiency measurement method, with the ultimate goal of a production-line-standardized transfer efficiency method. The EPA program was designed and initiated to develop the necessary background and research data to permit development of a standardized transfer efficiency test method. To ensure as broad participation in the program as possible, numerous sources in the industry were contacted and their assistance solicited where possible. In numerous instances equipment, personnel, and facilities were donated to support the program. Three systems are discussed: air-atomized conventional, air-atomized electrostatic, and airless spray.