Black out blinds, shutters, sash windows

[maw86]

We have recently installed plantation style shutter over sash windows in our bedroom (bog standard victorian terrace style). They're from 'Shutterley Fabulous' who I think team up with John Lewis. They let in loads of light and I was hoping to install blinds behind the shutters to make it darker (baby 2 due) but can't find any that fit and Shutterley Fabulous aren't being much help - apparently it's a very narrow gap?! Anyone have experience of this or advice? I'd rather not stick up the tommy tippee travel blackouts if possible.. !

Following for ideas. We bought a house with shutters and, while great in many ways, they let in too much light in summer.

Our stopgap solution was to screw small cup hooks into the wooden baton above the shutters, then hang panels of blackout fabric on loops from them in front of the shutters each night in summer. It works but is a bit of a faff so looking for a more permanent solution.