Discrete uniting bands which are used in a filter tipping machine to connect filter plugs with plain cigarettes consist of foraminous material, and the permeability of such material is varied, when necessary, by changing the quantity of adhesive which is applied to the uniting bands prior to convolution around the respective plain cigarettes and filter plugs. This ensures that each convoluted uniting band admits a preselected quantity of cool atmospheric air into the column of tobacco smoke when the respective filter cigarette is lighted. The paster which applies adhesive to a continuous web which is about to be subdivided into uniting bands is adjusted in response to signals which are generated by a testing device for the wrappers of successive filter cigarettes. If the permeability is too high, the paster is adjusted by reducing or increasing the quantity of adhesive which is applied to successive unit areas or unit lengths of the running web. This can be achieved by changing the thickness of the layer of adhesive or by changing the area of that portion of each unit length of the web which is coated with adhesive.