Venetian Blinds That Reflect And Attract Heat
Venetian blinds silvered on one side would be able to reflect the sun’s heat in the summer. They would be painted a dull black on the other side to absorb heat in the winter.
By L.S.Nickel, Carlisle, Pa.
These modern-day aluminum Venetian blinds are the nearest I could find although they’re not painted dull on one side! (affiliate link)