HOW TO CHOOSE YOUR DUVET
Higher quality duvets will provide a wider comfort range; they will be warmer in the winter and cooler in the summer than lower quality duvets. This is because higher quality down is better at all the things that down is famous for (insulation, lightness, breathability, etc.) than lower quality down. Higher quality down-proof fabrics also contribute to better breathability.
Most duvets are available in three weights: Although they can be called various things by different manufacturers, ultimately they can best be described as Winter, Classic, and Summer. Winter weight duvets are recommended for average sleepers in cool to cold bedrooms. Classic weight duvets are recommended for warm sleepers and for heated bedrooms. Summer weight duvets are recommended for very warm sleepers in warm conditions.