dies are disclosed for forming sheet - like extrudate of fluent material , such as a film of thermoplastic or solvent - plasticized material , or a liquid coating , e . g . a photographic coating , on a continuous support web . the dies include inner and outer cavities with the fluent material being supplied to the center or an end of the inner cavity . between the inner and outer cavities there is an inner slot and between the outer cavity and the exterior of the die there is an outer slot . the inner cavity is open at one end , if end fed , or at both ends , if center fed . the open end , or each open end , is closed by closing means which are detachable for allowing access to the inner cavity for cleaning and inspection . a member is located in the cavity extending from the open end or each open end . the member serves to reduce the effective flow path for fluent material in the inner cavity . by appropriate selection of the shape of the member , uniform flow rates of fluent material through portions of the inner slot adjacent the member may be achieved . by providing a plurality of interchangeable differently shaped members , a plurality of different combinations of rheologies and flow rates of fluent material may be extruded while maintaining uniformity of widthwise thickness uniformity of the extrudate . the invention is also applicable in embodiments in which there is only a single cavity and a single slot .