vertical blinds - showthrough

I dealt with this situation in an east-facing bedroom by treating the curtains as cosmetic and fitting a light-excluding roller blind behind them. I got mine in John Lewis. If you cut it to size accurately so that no light gets round the edges it's very effective.

made for the purpose. You can get ones which have a metalised backing which allow next to no light to pass.

IKEA have done corrugated cardboard roller blinds in the past.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember dave saying something like:

You can get vertical louvre blinds that are made out of black fabric, yes. They're not totally blackout, but very good at cutting it out. See any louvre blind supplier.

In article , dave writes

As others have suggested, 'blackout' is the keyword you are looking for. Searching for "vertical blind" +blackout gives plenty of sensible hits (although there are a few duffs from suppliers of vertical blinds who also do blackout roller blinds).