A duvet cover should fit the infill snugly - up to 6" smaller all around - to ensure that it doesn't shift. I have even put a king infill into a queen cover, with cosy results. Please measure your duvet, as infill sizes are not standard.
Material: 100% Linen. Pinstripe
twin 68" wide x 88"
queen 85" wide x 88"
king 106" wide x 90"
calking 106" wide x 98"
Care: Machine wash with a small amount of gentle detergent, not Tide. Tumble dry on hot or medium, and remove from the dryer while still very slightly damp so wrinkles do not set. Shake the fabric out flat and smooth it with your hands. If you can dry outside, let fresh air and sun work their magic.