Imperial Sugar Co. has extended the single-serve concept to brown sugar, in a bid to help cooks avoid the messiness of measuring out portions. Imperial, based in Sugar Land, Texas, is marketing light brown sugar in quarter-cup pouches, trade-named Redi-Measure, which come 12 to a paperboard carton. The pouches are clear printed film, and the carton has a die-cut window that opens onto the rear of one of the pouches, allowing a clear view of the product. Another die-cut window on the carton’s side panel lets consumers see the edges of the pouches.