Class I and Short Line locomotive owners specify DuPont Corlar / Imron Systems. Locomotive rebuilders prefer these high performance systems because of their durability, appearance, and ease of application. Union Pacific uses DuPont waterborne base / clear systems in North Little Rock, Ark.  CSX in Huntington, W. Va., and Norfolk Southern in Altoona, Pa use fast-dry DuPont base color followed by Imron 611P polyurethane clear. In Beech Grove, Ind., Amtrak uses long -lasting Imron and Corlar finishes for locomotives.