Buying secondhand without the guesswork

A twelve from 1974 is not a twelve from 2004, and neither is an Italian 44 or a Japanese M. Sizing is a convention, revised quietly and often, and it carries no information across decades or borders. What does carry is a measurement in centimetres, taken flat, from a garment that already fits the person who will wear it.

Start at home rather than on the rail. Take the coat or the shirt or the trousers you reach for most often, lay them flat on a table without stretching the cloth, and write down four numbers. For anything with sleeves: chest measured across from underarm seam to underarm seam, shoulder point to shoulder point across the back, sleeve from the shoulder seam to the cuff edge, and back length from the base of the collar to the hem. For trousers: waist across the top of the waistband, rise from the crotch seam to the top of the waistband at the front, inseam, and the width of the leg opening. Those numbers are the only thing worth quoting to a seller. Ask for them flat and in centimetres, and ask which points were used, because a chest taken two centimetres below the armhole reads differently from one taken at the seam. Photographs are close to useless for fit. A garment pinned at the back of a mannequin looks tailored, a garment on a hanger reads a size too narrow through the shoulder, and neither can be argued with after the parcel arrives. Of the four, the shoulder is the one to match exactly. A side seam can be let out or taken in, a waistband can be moved by two or three centimetres, a hem can be raised for the cost of a coffee. A shoulder seam sits over a set sleeve, a canvas and often a pad, and moving it means dismantling the top half of the garment. On a jacket that is several hours of skilled labour, which is usually more than the jacket cost.

Once the measurements agree, the composition label tells you more about what you are buying than any name stitched beside it. Brands change ownership, factories and specification constantly. Fibre content is a description of the object in your hands.

Wool at a decent weight can be pressed back into shape, rewoven where it is holed and worn for another twenty years. Linen and cotton launder and improve. A blend of wool with fifteen per cent nylon is a hardwearing coat cloth and nothing to be sorry about. Viscose drapes beautifully and loses strength when wet, so a viscose dress that has been washed rather than cleaned may already be weaker than it looks. Anything with elastane in it and a date before about 2010 should be assumed to have no recovery left, whatever the label promises. Read for fibre first and let the label brand come second, because a good cloth from an unremarkable maker outlasts a poor cloth from a famous one. Then the faults. Most damage is worth repairing and is priced into the tag, which is the pleasure of the trade: a lost button, a split lining, a broken zip, a moth hole or two in a lambswool jumper that a darner will close for very little. Fraying at the cuff of a shirt can be turned. A worn trouser hem can be shortened by a centimetre and disappear. Three faults cannot be repaired at any sensible price. Moth damage spread across a whole panel rather than in isolated holes, where the fibre has been grazed thin and the cloth will simply continue to give way. Perished elastic anywhere structural, in a waistband, a cuff or a shoulder, since replacing it means unpicking the construction it is sewn into. And a dropped shoulder in a knit, where the yarn has stretched along the line of a hanger and set: knitting has no seam allowance and no memory of its original dimensions, so there is nothing to pull it back to. Put those three down and walk on.