Rob, in 1/1200 scale scratch building I use monofiliment fishing line painted black for cannon barrels. Cut in segments for cannon: 4lb test are 6 pdrs; 8lb test are 9 pdrs; 12lb test are 12 pdrs; 20lb test are 24 pdrs; 30lb test are 32 pdrs, etc. Easy to work with and PVA glue works well to bind them to the 110lb card carriages.