Blackout curtains that aren’t plasticy or too warm!

[Berangere]

This recent warm weather had made me realise how awful the blackout curtains are in DS’s room. We recently moved house and are using the cheap ikea blackout curtains (about £15!) for the time being, but they’re turning his room into even more of a sauna! It also looks like a flimsy plastic shower curtain.

We have thick blackout Roman blinds being fitted in 2 weeks time but I think he will still need a thicker/darker curtain.
Any recommendations for dark/blackout curtains that aren’t plastic backed (or plastic feeling)rubbish, make the room too warm or look awful?

We use Dunelm M2M for curtains & (roman) blinds.
Great quality, lovely fabrics, good insulating qualities and the blackout material doesn't look any different to their normal lining.

My DD has ones from John Lewis that are fab. Plus they have glow in the dark stars on them..! 😂

These ones...

The windows in my son’s room are quite small so what I did was just tack some old white muslin squares on the outside to block and reflect the sun and now the blackout film on his windows doesn’t absorb all the heat! It’s ugly on the outside but does the job 😂