wrote in message
oups.com...

I thought with cotton canvas you were supposed to water it when new so
that the fibres swell and make it waterproof. Iseem to remember that's
what was done with tents in the olden times.

But as it dries the fibres shrink again :-)

Closely woven canvas will withstand a certain amount of rain on its surface
because of that property but if it's touched on the inner surface the water
will come through.

Mary