Thermal lining material for curtains

[AnnOnymity]

Can anyone recommend a website/supplier for buying thermal lining material for curtains? I don't know if they're all much of a muchness or vary in quality?

Have tried (and failed) to buy in local fabric shops so it need to be from an online shop.

I'm about to make curtains for massive windows so the ready ones (Dunelm?) are too small.

I bought my thermal lining from John Lewis , though it was a while ago. Even if it is not on their website, trying giving your local branch a call and they should be send it out to you if you can't get to the actual shop.

Oh, that's a good idea. Didn't think of that.

Don't Dunelm sell the fabric too?

My local one doesn't sell fabric.