Looking on an online blinds retailer, and SWMBO is keen on the "thermal
blinds" on the basis that they might save cash, but I'd prefer (in the
same colour) the blackout blinds, as they, er, provide blackout which the
thermal ones don't seem to do.

Retailer sadly doesn't seem to have any data sheets on the different
materials.

Any guesstimates for effectiveness of thermal blinds vs blackout blinds as
a money / energy saving feature?

Cheers!

Matt