Abstract: A method and apparatus for the preparation of controlled and reduced density reconstituted tobacco materials comprising injection of inert gas into a low moisture tobacco composition maintained at an elevated temperature and paste-like consistency. Preferably, the inert gas is heated to a temperature within about 40.degree.C of the composition prior to injection, and extruder means comprising high and low pressure zones is employed, with the point of gas injection selected to lie within the low pressure zone of the extruder or at the inlet port of a gear pump positioned after the extruder. Reconstituted tobacco materials (usually of sheet configuration) produced are characterized by even texture, uniform appearance, steady burning, and desirable taste, and can be prepared at densities lower than natural leaf.