Why are so many called stools?

Because the object is the same one. A backless upholstered bench can be described as a stool, a long stool, a bench or a window seat, and dealers use whichever word suits the piece. On Sellingantiques, "stool" runs through 151 of 335 titles against 31 using "seats". Plenty of listings carry two or three of those words together.

What woods do they come in?

The timber splits four ways. Mahogany leads with 89 titles, then walnut in 48, oak in 23 and rosewood in 19. Beyond those, beech, birch, elm, pine, satinwood, burr maple, padouk, Chinese huali and gonçalo alves each turn up only once or twice.

How often do pairs appear?

Roughly one listing in ten is a pair, with "pair" occurring in 35 titles. Pairs cluster in the upper half of the range. Larger groups are unusual. A set of four early 19th-century mahogany framed dressing stools is the only one in the samples.

Are French window seats common?

French is the one foreign origin that turns up regularly, in about a tenth of titles, often on gilded, painted or caned frames with Louis-style legs. Other origins are scarce and varied. Italian, Swedish, Dutch, Irish, Scottish, Chinese, Anglo-Indian and Syrian or Damascus pieces each appear only a handful of times.

What dates do these run between?

The dated field spans 1800 to 1930, and 155 listings carry a clean year. The profile clusters late, with the 1890s and 1900s strongest, then Edwardian, the 1880s and the 1920s. Regency and the 1860s carry the earlier weight. Georgian and 18th-century labels occur but are a small minority. The single commonest period entry is the unspecific "19th Century", used 80 times.

Do any unusual forms turn up?

A few oddities surface once each: a demilune seat in original paint, a double-sided bay-window seat, a japanned duet stool, an X-frame carved with hunting dog heads and a curule stool in gilt. Around 40 come to market in a year, and 138 different dealers have listed one, so almost no dealer handles them regularly.