My mother-in-law got new sheets for us, and I started putting them on immediately. However, she said that I must wash them first. Should new sheets be washed before using them?

It is a scene that plays out in bedrooms all over the world: you unbox a crisp, beautifully folded set of brand-new bed sheets, and your first instinct is to stretch them over the mattress immediately. There is nothing quite like the sleek smoothness of fresh linen, after all.

But if you have ever had a mother-in-law pause the process to insist, "You absolutely must wash those first," you might wonder if it’s a genuine rule of hygiene or just an old-school housekeeping myth.

So, who is right? Should you wash new sheets before using them, or is it perfectly fine to sleep on them straight out of the package?

Let’s settle the debate once and for all.

Why Your Mother-in-Law Is 100% Right

As eager as you might be to crawl into bed, your mother-in-law is giving you stellar advice. Dermatologists, textile experts, and manufacturing insiders all agree: you should always wash new sheets before sleeping on them.

Here are the three major reasons why giving them a quick spin in the laundry is essential:

1. Chemical Residues and "Starch"

To keep sheets looking pristine, unwrinkled, and perfectly stiff inside their plastic packaging, manufacturers treat them with chemical finishes. These often include sizing agents, starches, and even formaldehyde resins. Sleeping on these chemicals can trigger contact dermatitis, leaving you with itchy skin, rashes, or respiratory irritation—especially if you are prone to allergies or eczema.

2. The Journey from Factory to Bedroom

Before those sheets were beautifully packed, the fabric traveled through textile mills, industrial cutting rooms, and manufacturing floors, collecting dust, lint, and loose fibers along the way. Furthermore, multiple hands likely packed, shipped, and stocked them. A wash ensures you are stripping away the hidden grime of the supply chain.

3. True Softness Lies Post-Wash

That smooth, shiny texture straight out of the box is often just a temporary chemical coating. Washing the sheets breaks down these stiff manufacturing agents, opening up the cotton or linen fibers. Your sheets will actually feel significantly softer, more breathable, and more comfortable after their first wash.

What Should You Do? (The Best First-Wash Method)

When you are ready to prep your new sheets, don’t just throw them in on a random cycle. To maximize their longevity and softness right from night one, follow this simple routine: