A natural coloured multi-purpose cord suitable for non load bearing applications. No6 is the standard cord for throw lines. Widely used in tab tracks [No4 for T60 and No6 for T70] although many people now prefer to use matt polyester.
Please note: to find the approx. diameter of the cord add 2mm to the size of rope quoted [e.g. No 4 sash is approx. 6mm diameter].