What wood are these sets usually made from?

Mahogany leads, named in 222 of the 892 titles, then oak at 140, walnut at 87 and rosewood at 53. Elm, ash, beech and pine fill out the country end. Yew turns up only in a few Windsor armchair and stick-back entries. It's the scarcest timber named in the samples.

Are sets of four always dining chairs?

Mostly they are. "Dining" appears in 497 titles and the exact phrase "dining chairs" in 475, so a little over half the archive says so outright. The rest covers kitchen and farmhouse seating, salon chairs, hall chairs, smoker's bows and library armchairs. Cast-iron garden chairs, chapel chairs, station chairs, ship's armchairs, children's chairs and counter stools each appear only a handful of times.

How old are most of them?

The bulk is nineteenth century. "19th Century" and "Victorian" together cover about a third of all listings, and both are approximate labels rather than precise ones. After that comes a substantial early twentieth-century tail, with 1920s, 1900s and 1930s all well represented. Regency, Georgian and Edwardian each hold their own share. The dated field runs from 1715 to 1940. Seventeenth and pre-1700 entries exist but are a thin tail.

Does harlequin mean the chairs don't match?

It means four chairs of the same type that weren't made as one set. They'll be close in pattern and timber without being identical. Dealers declare it openly: 25 titles say harlequin, and others use mix and match, matched or similar. A set made as one commands more than an assembled four.

Which back patterns come up most?

The balloon back is the one to know, named in 30 titles. It's a rounded, waisted top rail, mid-Victorian in feel. Bar backs follow at 18. Shield backs, slat backs, spindle backs, lath backs, hoop backs and fiddle backs each turn up in single figures.

How many sets of four come up each year?

Around 95 a year on Sellingantiques, listed by 167 different dealers over the archive as a whole. No single specialist owns the category. It's spread across the trade, which is part of why the range of type and timber is so wide.