With the season’s first storms behind us, it’s time to get serious about keeping out the weather. Indow Windows offers nearly invisible inserts (exterior storm windows can be so ugly), custom-made in just a few weeks. Based in Portland, Ore., yet used widely in New England — from a Romanesque hall at Bowdoin College to a Victorian in Belmont currently featured on “This Old House’’ — the acrylic panels, all of which block drafts and reduce noise, come in seven grades, including opaque, semi-opaque, and UV-protective. Inserts by Indow Windows, starting at $24 per square foot (including shipping) at www.indowwindows.com.