i would go for spun poly or hemp twine when you start to make the nets mate, it costs a bit more per roll but the nets are far superior to nylon.
i make mine with a 2 inch board ( 2 inch spacer= 2 inch mesh) and 40 inches long, shaped from 12 to 18 mesh wide.
i have found this is a good sized net
i have a book "net making for sport" if i can find it i will let you know and you can have it bud.
waidmannsheil!!