Honeycomb Shades 101

In cross section they are shaped — in their purest form — like one cell of a honeycomb. The angles of the surface create air pockets that trap the air. They are insulators against cold air transferring through the window into the room in winter and heat transferring into the room in the summer.
Since their first introduction, we now have single, double and even triple honeycomb shades, in cell sizes from 3/8-inch to a whopping 2 inch. Optional reflective backing increases the heat reflective properties, and an opaque coating on fabric, applied on the inside of the cell can make them room darkening. Typically made of polyester, the shade can resemble fabric from the weight of a delicate sheer all the way to a nubby textured natural.
Nothing earth-shaking happened to honeycomb shades until Hunter Douglas introduced the Architella shade in 2010.
They added a second honeycomb within the honeycomb, creating 3 inner insulating pockets. and this year introduced a second inner cell. The first Architella was tested at providing an R-value of 7.7 and more, the additional pockets have increased this rating by 20 percent. So these are the still the most energy-efficient manufactured window coverings. Consider that up to 25 percent of your heating bill goes directly out your window. These shades do what they say they will do.
Honeycomb shades can be mounted inside a widow frame with little clearance, some only need 1 1/2 inches of sill depth for a flush mounting. With several types of lift systems, they are also available as a top-down shade. They can be combined so you actually have 2 shades on one headrail -one sheer for daytime privacy light filtering and one opaque for sun blocking or night privacy. And they can be mounted horizontally, making them perfect for patio doors because they also compress into a very small stack.
I was at the introduction of all the new Hunter Douglas offerings last Friday. They are so confident in the Architella shade that they are phasing out all the single-layer cell shades. And they lowered the prices too. Gotta love that.