Every coat has a small label sewn into a side seam, and most people never read it. It lists what the fabric is made of, in order from the most to the least, as a percentage. That one line explains a lot about how a coat will sit on the shoulders, how it moves when you walk and how it looks after a season of wear. Here is how to read it without any fashion jargon.
In Europe, fibres on a clothing label are listed from the biggest share to the smallest. A coat that says "70% polyester, 30% wool" is mostly polyester with some wool. A coat that says "90% wool, 10% polyamide" is the other way round. The label does not say how good the wool is or how heavy the cloth is, so treat the number as a clue, not a verdict.
Wool fibres are naturally crimped, a little like tiny springs. That is why a wool-rich cloth tends to hold a crisp shoulder and a straight hem, shrug off creases and feel warm without feeling stuffy. Polyester is a fine, smooth fibre. It is light, cheap and hard-wearing, and it tends to drape softly and catch the light with a slight sheen. Viscose drapes too, but creases more easily. Polyamide (nylon) is usually added in small amounts for strength.
None of this makes one fabric "good" and another "bad". A soft, fluid coat is a perfectly valid look. The point is to know what you are getting so the coat matches the outfit you have in mind.
Turn the coat inside out at the side seam and find the label. Three quick checks go a long way. First, look at the first fibre named: if it is polyester, the coat will behave like a polyester coat whatever the hanger says. Second, rub the cloth between your fingers: a matte, slightly fuzzy surface suggests more wool, a smooth and shiny one suggests more synthetic. Third, hold a handful of the hem in your fist for ten seconds and let go. Wool-rich cloth tends to spring back smooth; some synthetics and viscose blends keep the creases.
The label tells you what the coat will do. The outfit tells you which of those things you want.
A wool-rich coat suits outfits built on clean lines: straight trousers, a fine knit, leather shoes. Its crisp shoulder does half the work, so the rest can stay simple. A coat with a lower wool share is happier with relaxed outfits: wide jeans, a chunky scarf, trainers. It moves more, so it reads as casual even in a dark colour.
Colour interacts with the fabric too. Black and navy in a shinier synthetic can look flat and glossy under shop lighting; the same colours in a matte wool look deep. Lighter tones like beige, grey and camel hide the difference more, which is one reason they are the safe choice at a lower price. If you want a coat to look more expensive without paying for it, choose a plain colour, a simple cut and a matte surface, and skip heavy shine and large patterns.
Care matters as much as fibre. Wool-rich coats like brushing and an airing between wears, and an occasional dry clean. Synthetic-heavy coats often tolerate more, but check the care label before you wash anything. And remember the greenest coat is the one you already own: re-wear, repair a button, or look second-hand for a wool-rich coat before buying new.