The objective of this poster is to describe the smoking behaviour and dosimetry studies carried out to determine the effect of design changes, in particular increase in paper permeability at a range of cigarette pressure drops (58 - 125 mmWG). The experimental format for conventional dimensioned products involved using filter pressure drop, filter ventilation and paper permeability incorporating a statistically based central composite design. Two smoking behaviour and dosimetry studies were carried out. The five products chosen from the Virginia blend type tobacco matrix for the first study comprised two ~6mg products and three ~10mg products only differing in their paper permeability. Three pairs of ~6mg, ~7mg and ~9mg products from the 1:1 Mix of the Virginia and Burley matrix, at different pressure drops differing only in their paper permeability were selected for the second study. At a total cigarette pressure drop of ~87 mmWG, increasing paper permeability from 35 to 69 CU had little or no effect on the consumers' smoking behaviour; the dose obtained and perceived sensory intensities of ~6mg & ~10mg products in study 1. However, increasing the paper permeability from 33 to 75 CU at a total cigarette pressure drop of 58 mmWG resulted in relatively higher tar but significantly higher nicotine delivery in study 2. There were no significant differences in the smoking behaviour or perceived mean sensory scores between the two products. Increase in paper permeability from 33 to 75 CU at higher cigarette pressure drop = 87 mmWG had little or no effect on the consumers' smoking behaviour; the dose obtained and perceived sensory intensities of ~6mg & ~9mg products