Denim is graded in terms of weight per square yard of fabric, in three categories: light, medium and heavy. The material usually weighs from 5 oz. to 20 oz., although exceptions of extremes like 30 oz. do exist. Most jeans are made of 12 or 14 oz. denim, while lighter denim is mostly used on skirts, dresses and shirts. Weight is a matter of preference, but heavyweight denim can be more durable over time. Heavy denims also tend to create thicker ceases and honeycombs, plus they’re warmer. But remember: just because a fabric is heavier weight, it doesn’t mean that it’s guaranteed to last longer.