Changes in the propensity of cigarettes to ignite upholstered furniture and bedding could reduce fire losses significantly. This paper describes fundamental and empirical studies of the effect on ignition propensity of varying cigarette characteristics. Reduced tobacco density, circumference and paper porosity were especially effective. Energy transfer from the cigarette to the substrate was measured and relationships between cigarette combustion behavior and ignition propensity were explored, Using these data, computer modeling of the cigarette on a substrate manifested key features of the ignition process. A fully-documented technical report is available. [1]