What to look for when buying a wool blazer

A wool blazer is one of the few pieces of clothing that genuinely improves with age if it is made well and looked after. It is also one of the easiest pieces to get wrong, because the things that make a blazer last are mostly invisible at first glance. Grace has been buying and selling blazers for fifteen years. Here is what she looks at before anything else.

Fabric weight and composition ¶

The weight of the cloth is the first thing to check. A blazer intended for three-season wear should be in a fabric between 280 and 380 grams per square metre. Lighter than that it will not hold its structure; heavier and it becomes a coat. Boiled wool sits at the heavier end of this range and has the advantage of being self-structured, meaning it does not need interfacing or padding to hold its shape.

Pure wool is preferable to wool blends for longevity, but a small percentage of nylon (up to around 5%) in a suiting cloth is not a problem and can improve durability at stress points. Avoid anything with more than 20% synthetic content if longevity is the goal.

Construction: what to check in the fitting room ¶

Turn the blazer inside out and look at the seams. On a well-made blazer, the seams will be finished cleanly, the lining will be attached by hand at the hem (you will see small, even stitches rather than a machine-sewn line), and the buttons will be sewn through a small backing button on the inside to prevent the fabric from tearing over time.

Check the pockets. On a good blazer, the pockets are functional and the pocket bags are made from a proper lining fabric, not a thin cotton that will wear through quickly. Welt pockets should lie flat against the body without pulling or gaping.

Fit: the shoulders are non-negotiable ¶

The shoulder seam is the one part of a blazer that cannot be altered without significant cost and effort. Everything else, the length, the waist, the sleeves, can be adjusted by a competent seamstress. The shoulder cannot. When you try a blazer on, the seam should sit exactly at the edge of your shoulder, not hanging over it and not pulling inward.

Sleeve length is the most common alteration and the easiest to do. A sleeve that is half an inch too long is not a reason to leave a blazer on the rail if everything else is right.

A note on lining ¶

A silk or silk-blend lining makes a blazer easier to put on and take off, more comfortable to wear over other layers, and longer-lasting overall. Polyester linings are cheaper and more common, but they do not breathe and they tend to degrade faster than the outer fabric, which means the lining fails before the blazer does. If you are buying a blazer to wear for ten years, the lining matters.

The boiled wool blazer at Birch Citrine is in-store now in two colourways. If you want to try it on and talk through the fit, come in any day Monday to Saturday.