I regularily read the current topic list at the bottom of the main page and sometimes notice that there is a request for sails film, refered to as draughting film, well while looking in the loft for crystals in the multitude of boxes etc, I noticed I had 3 rolls of draughting cloth (blue).
Has anybody any idea if this is used for sails, in the back of my mind from my draughting days, they said it turns into just cloth if it gets wet as the wax coating gets 'washed' off, well I cut a corner off the roll and tried it and yes it turns into just cloth - sort of, the ends get frayed and the sheen goes, not sure if it is suitable for sails though.