Cabbages and net(Curtains!)

A lady on our lottie uses net curtains. I reckon she would have more success if she sewed them together to stop the gaps as they are really strong. Interested to know how the playing hoops come in?? We use alcathene pipe and wooden stakes as a frame for netting.

Hoops would be the frame, yep. And if I do end up with lots of net curtain panels, then yes, would be logical to sew/ attach together.

Have see children's playing hoops be used to create small polytunnels.
I'm just wondering as to whether enough light would pass through them, whilst keeping bugs out.

I have a lot of old nets and don't have a problem with light. I use clothes pegs to hold it tightly to the hoops.

Just don't use te old curtains that look like lace, the butterflies get through the holes. You want the nets without many holes, plain nets or voiles are ideal

Most nets will let plenty of light in, the problems are durability and strength. Durability because they will be exposed to loads of UV, far more than net curtains are usually exposed to (hot and cold weather also removes plasticiser from plastics, rendering them brittle), and strength because you need to be able to attach them to the hoops, or at least tie them down, or sew them together. Too weak and they will rip.
Sewing netting is something I have done a lot of this year, having been trained back when I was a tree nurseryman dealing with nets hundreds of feet long, and it is nice and relaxing if you have nothing else to do, it's sunny and you have somewhere comfy to sit.(Music is good too.) If not, do it indoors in good light on a wet day when you are desperate to be out gardening. Use contrasting, zig zagged thread so that if you are placing a net you can see at a glance when it is stretching or ripped.
Personally I have tended to use cheap insect screen mesh door and window panels as sold by Lidl's and Aldi. This was because I couldn't get near a garden centre, and was only growing in very small patches anyway. They have lasted years, are strong, and being available in black as well as white have been much more unobtrusive than normal nets, which is nice.
More recently I have been using a large patch of old Enviromesh given to me by a friend, and smaller new pieces of Enviromesh-type netting from a garden centre. These I had to patch in the first case, and sew to fit in the second. Netting is right there at the top of my "can't do without, must spend money" list, so although I'd say yes try net curtains, I'd also say start saving for investing in Enviromesh or something like it, quite apart from anything else, it keeps the heat in better thus speeding up growth at both ends of the season. Enviromesh is just so much more robust, it is a delight to work with.
A point worth pondering is that you are probably only thinking of using netting on your brassicas, but all sorts of crops will benefit - eg, my tardy root crops have grown much faster since I netted them - so you want to be able to keep out flea beetle etc, not just cabbage whites. Net curtains won't keep out whitefly, in my experience, so may be a bit limited.
Think of using wooden rectangular frames if you can, instead of hoops. I know alkathene piping hoops are popular and easy to get - I use them - but when it comes to harvesting and weeding, they are a pain.They are also a bit too flexible when weighted with heavy snow unless stiffened with canes. Far better to make a rectangular frame (or several smaller ones if you wish) of 35mm wood and tack or staple the netting on (better for using small bits). These frames you don't need to weigh down or tie the netting to, and you can just tip them sideways or remove them when accessing the crop. You can start by making short frames, then lengthen them later as your crop grows by putting extensions into the ground, and placing the uprights of your frame on top of these, fastened by means of a nail inserted between a single staple on each bit of wood. Either allow a skirt of excess netting when making the original frame in order that the frame can be used, or have a long thin strip of netting that you can use temporarily on the extensions.
IMHO !

Be aware that some plastics aren't UV stable, and will disintegrate into a million shards after a year or two.

I use net curtains if I can find them cheap: they last much longer than fleece

Yes, I hadn't thought of it, but cheap plastic toys are the absolute worst for having volatile plasticisers. (We must be insane to allow these chemicals in children's toys.The Romans with their lead water pipes had nothing on us.) Given that the plasticisers are all endocrine disruptors, and will be lost into the soil where you grow food via the precipitation that your plants take up, another good reason to use alkathene pipe from a builder's merchants; it is designed to have a twenty year lifespan with very limited loss of plasticiser into water. (Although hot water compromises this to some extent.)
Or better still, just use untanalised wood.

I tried some wooden frames covered with enviromesh last year but they all collapsed under the weight of snow. The ones covered with scaffold netting didn't. I am using the black alkathene pipe this year as it is UV stabilised.

Aye, the devil's in the detail ! You've got to be dead careful about what size of wood you use and what fixings you use to put it together. If the snow is heavy enough - not just the depth but the percentage of water contained in the snow - nothing will stand up to it really, but a can with a yogurt carton on top to push up the middle of the netting will make a difference.
Of course it used to be that you wouldn't have netting on if it was cold enough for snow, after all it does no good then. But now that we have such sporadic winter temperatures, with warm snaps in between that can produce pests, we have this new problem.

Lead pipes are hardly something to boast about with the Romans. A great deal of them died from lead poisioning!

Exactly. We think we are clever because we use copper for water pipes, then we expose ourselves to thousands of endocrine disruptors...

I hate to tell you this but there are miles of lead water pipe still in use in this country and unless they are disturbed they are perfectly safe.

Colin.

Yes Colin, we humans do seem to be very good at classifying things as villains and heroes when it is not really that straightforward...particularly when it comes to toxicology or risk. (I'll pipe down now.)

I use lots of net curtains and voile on my allotment. I had a blowaway greenhouse which lived up to it's name so have used the frame to make a 3ft frame all around a large bed with netting around and above which has been successful. I have picked up cheap voile and nets at car boot sales and charity shops, some of which I have sown together.

I am planning to make some more permanent frames though, probably stapling or nailing some of the netting onto it, as some has blown about too much when it has been very windy.