Which zipper is used on a duvet cover?

Q: Which zipper is used on a duvet cover?

A duvet cover uses a size 3 or size 4.5 nylon coil, closed-end at both ends, with a plastic slider and a soft pull. The size 3 is enough for a lightweight cotton cover; the size 4.5 is better on a heavy linen or a large king-size opening where the tape has to span a long distance without sagging. Set the zip 15 mm inside the seam so the chain is protected during washing, and use a tape that has been pre-shrunk.

• Size 3 for light cotton; size 4.5 for linen or large sizes.
• Closed-end at both ends, plastic slider.
• Pre-shrunk tape, set 15 mm inside the seam.

The common pitfall is untreated tape, which shrinks in a hot laundry cycle and puckers the whole opening so the cover no longer lies flat. The second is an exposed metal slider at the corner of the bed, which is uncomfortable and can scratch. A plastic slider with a fabric pull solves both, and a slightly longer zip makes it easier to insert a duvet without straining the chain.