Transparent single walled carbon nanotube (SWNT) networks were printed on plastic substrates. Nanotubes in the network form small bundles, and the authors evaluated the dc conductivity (sigma(dc)) as a function of the average bundle length (L-av) in the network. They find sigma(dc) to vary as sigma(dc)similar to L-av(1.46) for bundles of the same diameter and give a qualitative argument for why this agrees with a model where the resistance between SWNT bundles dominates the overall network resistance. (c) 2006 American Institute of Physics.