Kid's School Blazer

Lapels, a set-in sleeve and a crest at the breast mark out a school blazer. It is sized by chest measurement in inches rather than by age or height. That one difference catches most families out, because a child whose height reads size 12 can need a 30 inch chest instead. The two numbers move at different speeds.

Structure comes from an interlining, a layer between the outer cloth and the lining that holds the shape of the front panel. School blazers almost all use a fused interlining, bonded on with heat. This is inexpensive and can bubble along the front edge if the jacket ever meets a hot wash or a hot iron. Cloth is usually a polyester and viscose blend around 7 to 9 ounces, chosen because it survives machine washing that a wool jacket would not. Full lining adds warmth and hangs cleaner. Half lining leaves the back open and suits districts where the jacket is still being worn indoors in June.

The everyday layer is a Uniform Cardigan and this is the formal one, appearing on assembly days, photograph days and trips. The Parka in our Kid's Outerwear guide goes over a blazer in winter rather than replacing it, since a blazer offers no wind or water resistance worth counting on.

Schools that name a jacket on the list leave no choice, so the advice is to buy one and look after it. Sizing two steps ahead fails more visibly here than anywhere else, because a shoulder seam hanging down the upper arm shows in every photograph taken that year. Very warm terms are the reason to choose the half lined version.

Put a hand on the shoulder: the seam belongs on the corner, since that is the one measurement a tailor cannot move without rebuilding the jacket. Check the sleeve buttons are decorative rather than working, which is what allows a sleeve to be let down later. Note how the crest is attached, as an embroidered or stitched patch stays put while a heat applied one lifts at a corner within a year. Brush it after wear, hang it on a wide hanger, and read the label before assuming it needs dry cleaning.