Will posted this comment on the knitting container in my gallery (David Osborne) -
"Stupid humour aside Mr D, I have to say that this is a fine piece of work. The one-piece-of-card construction intrigues me. Did you use a flat "net" pattern then bend into shape? Did you use corrugated card? How did you prevent warping? I don't want to know your secrets unless you are prepared to produce a proper "public" tutorial (a lot of work I know). So I will continue to ponder. A pity that more people haven't posted comments in this gallery and many others, there's some great stuff here. Oh well.... Anyway, just thought I'd give credit where it's due. ("RESPEC Bruvver)
I will now go and visit other gallaries and leave polite comments......."

In order to respond to him and to share it with anyone else who is interested, I will answer here in Forum.
Yes, it is corrugated card, a good quality one from the sort of packaging you get with large electrical appliances.
Yes, I did use a "net" pattern.  To help with this, I made a tool for creating large circles.  This was a strip of wood with drilled holes at 2cm intervals for the insertion of a pencil at whichever radius I needed, a nail fixed at one end to hold the central point.  Smaller elements were with strong cereal package cardboard (No, Will, it wasn't the cereals that were strong!!).
Warping was prevented by laminating on both sides.
No, I'm not going to produce a tutorial on it, thanks.  Awright ole mate?

The reason there are not as many comments as you might expect is because that facility is quite new and bless Russ's cotton socks for creating the opportunity.
DavidO