Duvets 101 - What's All the Fluff About?in Our Story Share Choose from 3 duvet insert styles and find one that suits your needs: 1. Midweight Down Alternative Duvet Insert Machine washable and stuffed with hypoallergenic fill. 2. Down Duvet Insert Certified under the Responsible Down Standard (RDS). 3. All Seasons Down Alternative Duvet Insert Lightweight and can be kept on the bed year-round.