Low threshold fields of 1.6 V/mum and 2.6 V/mum were obtained for field emission from multiwalled carbon nanotubes and boron-doped multiwalled carbon nanotubes embedded in polystyrene, respectively. A Fowler-Nordheim analysis of the results together with sheet resistivity data illustrate that the higher carbon nanotube concentrations in a polystyrene matrix result in larger effective emission areas, at the expense of higher operating threshold fields. (C) 2002 American Institute of Physics.