I decided the sun room needed a bookcase, but it can't be too big because the room is small. Also, because it's windows on three sides, and open into the living room on most of the fourth, the only place I can put it, taking into account door sill and window sill projections, is 23" wide. So I found
these at Pier One.
I bought the shorter one today, because the taller one would probably be too overwhelming for the space. But now I'm thinking that I have three very similar cases that are between these two in size - 48" tall, with four shelves, one of which is in my "butler's pantry" and holds my cookbooks, which are, of course, tightly packed. So if the medium-sized one fits in the sun room, I can return the short one, and get the five-shelf one for the butler's pantry. Of course, this means emptying all the books out of it for the experiment.
The saleswoman told me I have thirty days to, as she put it, "play around with it" and change my mind if I want. So play I will.