Ironing and steaming: dots, temperatures and what not to iron

The iron symbol on a care label is one of the few that gives you an exact number, if you know how to read it: each dot stands for a maximum soleplate temperature defined in the ISO 3758 care-labelling standard. Match the dots to the dial and most ironing problems — shine, scorch marks, melted synthetics — never happen.

The dots

• One dot — cool, up to 110 °C. Synthetics: nylon, acrylic, acetate, polyester and elastane blends.
• Two dots — medium, up to 150 °C. Wool, silk, polyester-cotton blends, viscose.
• Three dots — hot, up to 200 °C. Cotton, linen, denim.
• A crossed-out iron — don't iron. Crossed-out lines under the iron — iron, but without steam.

Most irons print the same dots on the dial, so the label maps straight onto the setting. The full set of symbols is in the laundry symbol guide.

Order and preparation

• Iron cool fabrics first while the iron heats up, and hot ones last. An iron cools slowly, and a three-dot iron touching a one-dot fabric is how nylon melts.
• Test on a hidden spot with anything new or unlabeled.
• Iron inside out for darks, prints, embroidery and anything with a sheen. Shine — that glazed look on trousers — is the fabric's surface being flattened; the reverse side hides it.
• Iron cotton and linen damp, straight from the line or with a spray. Dry cotton needs more heat and more passes; damp cotton creases release in one.
• Use a pressing cloth — a clean cotton tea towel — over wool, silk and anything dark. Steam through it rather than pressing directly.
• Never iron over a stain. Heat sets it. See the stain removal guide first.

Steam

Steam relaxes fibers so the iron doesn't have to press as hard, which is gentler on fabric. It's what wool and most cottons want. Turn it off for silk and for anything whose label shows the no-steam symbol — water droplets can spot silk and some acetates. A garment steamer is the gentlest option of all for knits, suits and anything with structure: it de-creases without pressure and without touching the fabric.

What not to iron

• Anything whose label shows the crossed-out iron.
• Screen prints, vinyl lettering and transfers — they melt onto the soleplate. If a printed T-shirt needs ironing, do it inside out on a cool setting with the print face down on a towel.
• Waterproof or coated fabrics, and anything with a membrane.
• Velvet and corduroy — the pile flattens. Steam them hanging up instead.
• Sequins, beads and plastic trims.

Ironing less

Most creases come from the dryer and from clothes sitting in a heap. Shake garments out before hanging, take them out of the dryer while slightly damp and hang them at once, use the permanent press cycle for shirts, and hang the bathroom's steam on anything wrinkled during a shower. A lot of ironing is just undoing what a hot dryer did.

LaundryMax reads the iron symbol and its dots along with the rest of the label, so the right setting is in your closet before you plug the iron in. See how it works.