Wooden Venetian blinds that cut out light?

[Finallyspringishere]

Do these exist?

I have bought made to measure wooden 50mm slat blinds for my spare room. They don't cut out enough light and I will need to put curtains over them.

I wanted the same blinds fro my own bedroom, but I don't have room for curtains too. Do any wooden venetians work at cutting out light... or do I need to spend £££££ on made to measure roman blinds?

No blinds completely cut out light as it will seep in through the edges, even with a thick roman blind (though IME the latter cut out more light than wooden blinds).

Blackout material and velcro (attached around the outside edges of the window frame) are a relatively cheap and removable option.

The light is seeping in between the slats with these.

We used to have some john Lewis ones that were pretty good. A tiny bit of light came in at the edges but nothing through the slats.

Would they be pretty expensive made to measure?