Hello All-

I picked up some cotton canvas duck in Khaki color at WallyMart for real cheap.

Two questions:

Should I wash this mat'l before I start? It may have sizing in it but it's not quite as heavy as the Carhartt's that I wear @ work.

Should I add some to the seat measurement so it won't get tight/pull the pleats when I sit? This canvas doesn't give like a wool tartan mat'l.

Thanks for any feedback you can give.

Ray S.