Two very different services:
A self-service laundrette is a do-it-yourself service: you wash and dry your own laundry with water, in large machines, with no intermediary. A dry cleaner is a service entrusted to a professional who takes charge of your garments, often by dry cleaning (using a solvent rather than water), then presses them and restores their shape.
One is built on independence, volume and low prices; the other on expertise, care for delicate materials and finishing. They are not rivals: they answer different needs.
What to take where:
To the laundrette: all water-washable laundry, and above all the bulky items — sheets, towels, everyday clothes, duvets, blankets, washable curtains. You stay in control and usually leave with clean, dry laundry in under an hour.
To the dry cleaner: items marked with a P (« dry clean only »), suits and tailored outfits, coats — wool ones in particular — leather and suede, silk, evening dresses, rugs, and of course anything that needs professional pressing. A dry cleaner also handles the stains you cannot deal with yourself.
The golden rule: read the label:
To decide, the rule is always the same: look at the care label sewn into the garment. A tub symbol means machine washing is allowed, and therefore a laundrette. A P means the fabric is reserved for dry cleaning.
If in doubt about a valuable or delicate item, a dry cleaner is the safer choice. For everything else — the everyday and the bulky — a laundrette remains the simplest and most economical answer.