A winding form baselayer (20) has a flexible insulative substrate (22) on which a plurality of parallel spaced apart filament cable guides (24) are located. Optionally, the guides (24) can be formed by depositing a metal layer and etching out spaces (W) between the guides or plating the individual guides. A wound pack (28) is produced by winding a first filament layer (26) into the spaces (W) with subsequent layers wound over the first layer in conventional manner. In an alternate version, the filament cable guides (52) are etched into the top side of a metal sheet and the opposite side is etched into a diagonally arranged set of struts (56) which provide lateral resiliency for the entire baselayer (46).