How to read fabric care labels and bolt-end tags

Fabric care labels use five symbols, always in the same order: a washtub for washing, a triangle for bleaching, a square for drying, an iron for ironing and a circle for professional cleaning. Dots inside a symbol mean temperature (one dot cool, three dots hot), a bar underneath means a gentler cycle, and a cross through a symbol means do not. A bolt-end tag at the fabric shop adds what the care label leaves out: the fiber content, the width, the price per meter or yard and sometimes the weight, which are the four things you need before you buy.

What do the five care symbols mean?

The symbols are standardised internationally, with small differences between Europe, where a number inside the washtub gives the maximum temperature in degrees Celsius, and North America, where dots stand in for the number.

A label reading "40 with one bar, crossed triangle, square with crossed circle, two-dot iron" tells you: wash at 40 °C (105 °F) on a gentle cycle, no bleach, do not tumble dry, iron on medium. That is the typical label for a viscose or a cotton-viscose blend.

What is on a bolt-end tag?

Fabric sold by the meter does not come with a sewn-in care label; the information is on the tag at the end of the bolt, on a hang tag, or on a shelf label. Photograph it before you leave the shop, and ask for a copy if it is only on the bolt. A typical tag carries:

• Fiber content, in percentages: "100% cotton", "55% linen 45% viscose", "95% cotton 5% elastane". This decides the washing temperature, the shrinkage and the pressing heat.
• Width, usually 110, 140 or 150 cm (45, 55 or 60 in). It decides how much to buy: a pattern that needs 2.1 m (2 1/4 yd) on 140 cm may need 2.8 m (3 yd) on 110 cm.
• Price per meter or per yard, sometimes per half meter.
• Care, either as the symbols above or as a sentence ("machine wash cold, line dry").
• Weight, when the shop is thorough, in grams per square meter (gsm) or ounces per square yard. 120 gsm is a blouse weight, 200 gsm a trouser weight, 300 gsm and above a jacket or bag weight.
• Country of origin and the mill or designer, and for quilting cotton the collection name.
• Stretch, for knits, sometimes as a percentage; more often you test it in the shop.

If the tag says only "poly blend", "mixed fibers" or nothing at all, treat the fabric as a synthetic for pressing (low heat first) and test a square before deciding how to wash it. Reading fabric descriptions explains the trade names you will see online, where a tag's worth of information is spread over a product page.

How do you turn the label into a washing plan?

Pre-wash the fabric the way you will wash the finished garment, so that any shrinkage happens before you cut. The label gives the ceiling, not the rule: a cotton labeled 60 °C (140 °F) can be washed at 40 °C, and most sewists do, but a 30 °C (85 °F) label on wool or silk is a limit to respect.

A few rules that follow from the fiber content on the tag:

• Cotton and linen shrink 3 to 5 percent on the first wash, sometimes more. Wash and tumble dry once at the temperature you will use, press, then cut.
• Viscose and other rayons shrink more and weaken when wet. Wash on a gentle cycle in a mesh bag, dry flat or on the line, and expect a changed hand.
• Wool felts with heat and agitation. Hand wash cool, or steam the yardage instead of washing it, and never tumble dry.
• Polyester, nylon and acrylic barely shrink but hold creases set in by hot water. Wash warm, not hot, and take them out of the dryer promptly.
• Blends follow the most delicate fiber in them. A cotton-elastane jersey is washed like elastane: warm, no hot dryer, which degrades the stretch.

Pre-washing fabric goes into the how and the exceptions, and the shrinkage by fiber post gives figures by fabric so you can buy enough.

How do you set the iron from the label?

The iron dots map onto the dial of a domestic iron, which is usually labeled with the same dots or with fiber names. One dot is the setting for synthetics, silk and acetate; two dots for wool, polyester blends and viscose; three dots for cotton and linen. When the fiber content is a blend, press at the setting of the most heat-sensitive fiber and use steam to make up for the lower heat.

Test on an offcut before the garment, with a pressing cloth on anything dark, shiny or synthetic. Shine, a flattened nap and a melted patch are all one too-hot pass away on polyester and on velvet, and a scorch mark on cotton does not wash out.

Which labels tell you the fabric is a bad choice for the project?

Read the label against the garment, not on its own. A "dry clean only" fabric is a poor choice for a child's T-shirt or an apron that will be washed every week, however lovely it is. "Dry flat" on a viscose suits a blouse but is a nuisance on a full gathered skirt that holds a lot of water. A knit labeled "do not tumble dry" will lose its recovery if it goes in the dryer anyway.

Conversely, "machine wash 40, tumble dry low" on a cotton-linen blend is the label of an easy wardrobe. For the drape, weight and stretch the garment needs, which no care label states, see how to choose fabric for a pattern. Sewly's sewing guide lists the fabric amount for 110, 140 and 150 cm widths for the pattern you have drafted, so the width on the tag maps straight onto a quantity.

What should you write on your own label?

Keep a card with each cut of fabric: fiber content, width, the amount bought, the price and the care line from the tag, plus a note once you have pre-washed it. When the garment is finished, a small woven label or a note in a sewing journal with the care instructions saves you from guessing a year later. If you give the garment away, tell the person how to wash it; a handmade linen dress tumbled hot is a sad thing.