I'm thinking of getting Perfect Fit blinds for the bedroom; there are already thick velvet blackout curtains outside the (deep) window recess, but as the room is easily overlooked next to a road, I was thinking of getting some light filtering bottom-up blinds so that I could open the curtains occasionally in the day to get some light in.
Some of the blinds are pleated (single layer) and some are honeycomb shaped (kind of double layer pleats). I've read that the honeycomb ones are better at insulating against heat/cold. Cold isn't so much of a problem, but heat is. But I don't know whether it really makes much difference, and on the hottest days I can leave the curtains closed anyway. There are more options available in single pleats, and they are somewhat cheaper. But if it does actually make a difference to insulation/heat, then it might be worth paying the extra for honeycomb.
Has anyone got honeycomb ones? Did you notice a difference in the summer (or winter)? Is it likely to make any further difference beyond what the velvet curtains are doing?