The stack
A bed is 5 layers on top of a mattress
Every one of them gets the same three questions on its own page, in the same order, with the same headings. Fit, then heat, then wash. Listings sell these things as separate categories with separate vocabularies; on a real bed they are one pile, and a decision about any one of them changes the others.
Mattress Protector
A protector is a fitted skin that goes straight onto the mattress and stays there. Its whole job is to stop liquid, dust and body oil from reaching foam or ticking you cannot wash. In a linen closet it is the item people forget exists until the day it earns its keep.
- Washes
- Every two months, and immediately after any spill.
Mattress Topper
A topper sits on the mattress and changes what the surface feels like without replacing anything. It is also the single item most likely to break the rest of your bedding, because it adds two to four inches to a stack your fitted sheets were bought for. It is the layer with the most rules attached to it and the fewest of them printed on the front of the bag.
- Washes
- The cover, if it comes off, on the same schedule as your sheets. The foam itself, never, unless the manufacturer says otherwise on the label.
Sheets
Sheets are the layer you actually touch all night, and the only one in the stack that has to grip something. A flat sheet and pillowcases are cloth rectangles and behave like it. A fitted sheet is a piece of engineering with elastic in it, and it is the item in a linen closet that gets sent back most often.
- Washes
- Weekly for the sheet you sleep on, and weekly for pillowcases.
Comforter
A comforter is a quilted bag of fill that covers the bed. It is the layer most often bought for how it looks, and the layer whose one genuinely comparable number is printed least often. It is also the bulkiest thing you will ever try to fit in a home washing machine, which is most of what makes it difficult.
- Washes
- Every three to four months if it is under a flat sheet or inside a duvet cover. Every four to six weeks if it is the layer against you.
Pillow
A pillow holds a shape between your head and the mattress for eight hours, and then has to still be that shape tomorrow. It absorbs more of you than anything else on the bed. It is also the item where listing language runs furthest ahead of anything measurable, which is why this page spends more time on words than on products.
- Washes
- Polyester fill pillows every three to four months, if the label allows it. Foam pillows never go in a machine; the removable cover does, and the foam does not.