In article , Rod
writes
http://www.knowlenets.co.uk/shop/system/index.html

Thanks for your help, Rod.
I tried the above link with three browsers and none of them would load
the page! It might pay that company to use simpler HTML.
My garden centre has some stiffish black netting in a 2 metre width -
with a square mesh of about a centimetre.

I did look at your suggestion for metal posts - I just feel more
comfortable working with wood.

I reckon I've room for about 3 metres wide by perhaps 6 or 8 metres
long. It's a pity if internal supports are needed - but I suppose they
could be thinner - and for a double row of cordons using the internal
posts to hold the wires I would have to use two internals within the
three metres, which is perhaps a bit over the top?

The internal posts might be 2 x 2 and the top beams 2 x 1?
4 x 1 gravel boards at the bottom.

It comes out a bit expensive for an amateur gardener - maybe three
hundred quid - but it might be worth it in fun and education.
--
Chris