Laundry Symbols
Decode garment care label symbols for washing, drying, bleaching, ironing, and professional care. Covers all ISO 3758 international standard symbols.
Key features
- Full guide to ISO international care symbols
- Breakdown of washing, drying, bleaching, and ironing icons
- Plain-language explanations for even the weirdest symbols
- Quick reference for a safer laundry day
Guide
Laundry care symbols printed on clothing labels follow ISO 3758, an international standard that replaces written instructions with universal pictograms. These symbols work across all languages and tell you exactly how to wash, bleach, dry, iron, and professionally clean a garment without damaging it. Misreading a single symbol can shrink a wool sweater, melt a synthetic blend, or fade a dyed fabric permanently. The five base symbols represent five care processes: a washtub for washing, a triangle for bleaching, a square for drying, an iron for ironing, and a circle for professional cleaning. Every care label uses some combination of these five symbols, modified with dots, lines, and crosses to specify exact conditions. The order on the label always follows the same sequence: wash, bleach, dry, iron, professional clean. This consistency lets you scan any label quickly once you know the system. ## Washing Symbols The washtub symbol (a trapezoid shape representing a basin of water) is the foundation. A plain washtub means machine wash at the temperature indicated by the number inside or the number of dots. One dot means 30 degrees Celsius (cold). Two dots mean 40 degrees (warm). Three dots mean 50 degrees. Four dots mean 60 degrees. Five dots mean 70 degrees. Six dots mean 95 degrees (boil wash). North American labels may use temperature numbers directly instead of dots. A single horizontal line under the washtub means permanent press or synthetic cycle. This cycle uses a reduced spin speed to minimize creasing in synthetic fabrics. The agitation phase is the same as normal, but the spin phase slows down to prevent wrinkles from being set into the fabric. Two horizontal lines under the washtub mean gentle or delicate cycle, with both lower agitation and lower spin speed. These underline modifiers matter. Washing a delicate-marked garment on a normal cycle subjects it to spin speeds of 1000 to 1400 RPM and agitation forces that stretch fibers, break threads, and distort shapes. The temperature specified on the label is the maximum safe temperature, not the recommended temperature. Washing at a lower temperature is always safe for the fabric (though it may reduce cleaning effectiveness for heavily soiled items). If the label shows 60 degrees, washing at 40 degrees is fine. Washing at 80 degrees risks damage. A hand inside the washtub means hand wash only. Hand wash temperature should stay below 40 degrees Celsius. Gently squeeze the garment in soapy water. Do not wring, twist, or scrub it against itself. Wringing distorts the fabric structure, especially in knits and loosely woven materials. Hand wash items include delicate silk garments, wool sweaters, lingerie with lace or embellishments, and garments with beading or sequins. Use a clean basin or sink. Do not soak hand wash items for more than 10 to 15 minutes because prolonged soaking can cause dye migration. An X through the washtub means do not wash with water at all. This garment requires professional dry cleaning. Washing it at home with water will cause shrinkage, color bleeding, structural damage, or all three. Materials that commonly carry this symbol include silk satin, structured wool suits, leather, suede, garments with glued embellishments, and some technical coatings like waxed cotton. ## Bleaching Symbols The triangle symbol governs bleaching. An empty triangle means any bleach is safe, including chlorine bleach and oxygen bleach. Two diagonal lines inside the triangle mean only non-chlorine (oxygen-based) bleach is safe. An X through the triangle means do not bleach with any product. Chlorine bleach (sodium hypochlorite) is the strongest option. It whitens effectively but degrades protein fibers (wool, silk) and weakens cellulose fibers (cotton, linen) with repeated use. It also strips color from dyed fabrics. Use chlorine bleach only on white cotton and white cotton-polyester blends. Never use it on colored fabrics, wool, silk, nylon, or spandex. Oxygen bleach (sodium percarbonate) is gentler. It works by releasing hydrogen peroxide when dissolved in water. It is safe for colors and most fiber types but works more slowly and requires warm water (at least 40 degrees Celsius) to activate fully. Oxygen bleach is effective for removing organic stains (food, grass, blood) and brightening whites without the fiber damage caused by chlorine. The bleach symbol applies to all bleaching agents, including those in laundry detergents. Many detergents contain optical brighteners or oxygen bleach compounds. If a label shows no bleach, choose a detergent labeled "free and clear" or "no bleach" to avoid accidental damage. Optical brighteners are not technically bleach (they are fluorescent dyes that absorb UV light and emit blue light), but they can build up on fabrics and cause yellowing over time on some materials. ## Drying Symbols The square symbol covers all drying methods. A circle inside the square means tumble dry (machine dryer). Dots inside the circle indicate temperature: one dot for low heat (approximately 60 degrees Celsius exhaust temperature), two dots for medium heat (approximately 80 degrees), three dots for high heat (approximately 95 degrees). No dot means tumble dry with no heat (air fluff only). Underlines beneath the tumble dry symbol work the same as with washing: one line means permanent press cycle (lower heat toward the end of the cycle to reduce wrinkling), two lines mean gentle or delicate cycle (lower heat and reduced tumble action throughout). These modifiers prevent mechanical stress on delicate fabrics. An X through the tumble dry symbol means do not machine dry. Machine drying at the wrong setting is one of the most common causes of garment damage. High heat causes shrinkage in cotton (cotton fibers contract when exposed to heat and moisture simultaneously), felting in wool (the scales on wool fibers interlock permanently under heat and agitation), and melting or deformation in synthetics like polyester and nylon. Even low heat can damage elastic fibers (spandex, elastane, Lycra) over time, causing them to lose stretch and recovery. Natural drying symbols appear as variations of the plain square without the circle. A single vertical line inside the square means hang to dry (on a clothesline or hanger). This works for most everyday clothing. Two vertical lines mean drip dry (hang while soaking wet, allowing water to drip off without wringing). This method works well for items that are heavy when wet and would be difficult to wring out, like thick denim or canvas. A single horizontal line inside the square means dry flat. Lay the garment on a flat surface, ideally on a clean towel that absorbs excess moisture. This method is critical for heavy knits, wool sweaters, and cashmere garments that would stretch and distort under their own wet weight if hung. Reshape the garment to its original dimensions while laying it flat. Wool and cashmere can be gently stretched or compressed back to shape while damp. A diagonal line in the upper left corner of any natural drying symbol means dry in shade. Direct sunlight fades dyes (especially reactive dyes used on cotton and linen), yellows white fabrics (UV radiation breaks down optical brighteners), and degrades elastic fibers. Shade drying preserves color and fiber integrity. Dark-colored garments, silk, and activewear with spandex content should always be dried in shade. ## Ironing Symbols The iron symbol is self-explanatory in shape. Dots inside the iron indicate temperature: one dot for low (110 degrees Celsius, suitable for synthetics like polyester, nylon, and acrylic, as well as silk), two dots for medium (150 degrees, suitable for wool, polyester blends, and viscose), three dots for high (200 degrees, suitable for cotton, linen, and denim). An X through the iron means do not iron. An X over steam lines beneath the iron means do not use steam. Some fabrics react badly to steam: silk develops water spots, velvet pile crushes flat, and certain water-resistant finishes degrade. When ironing without steam, use a pressing cloth (a thin cotton fabric between the iron and the garment) to prevent shine marks on dark fabrics. Pressing cloths also protect delicate prints and screen-printed graphics. Ironing temperature matters more than most people realize. Setting a cotton iron temperature (200 degrees) on a polyester garment melts the fibers, creating permanent shiny patches or holes. Setting a synthetic temperature (110 degrees) on cotton leaves wrinkles because the heat is insufficient to relax cotton fibers. Cotton fibers need temperatures above 175 degrees to release wrinkles effectively. For best results, iron garments while slightly damp or use a spray bottle to mist them with water. Iron dark fabrics inside out to prevent shine. Iron silk with a pressing cloth on the lowest setting. Iron linen on high heat while damp for the smoothest finish. Never leave a hot iron face-down on fabric, even for a few seconds. The difference between ironing and pressing matters for tailored garments. Ironing involves sliding the iron across the fabric. Pressing involves setting the iron down, applying pressure, and lifting. Pressing is used for seams, creases, and structured garments like suits and dress pants. Sliding an iron across wool causes stretching and shine. ## Professional Cleaning Symbols The circle symbol indicates professional cleaning. A letter inside the circle tells the dry cleaner which solvent to use. "P" means tetrachloroethylene (perchloroethylene, also called perc), the most common dry cleaning solvent used worldwide. Perc dissolves oils and greases without water, making it effective for cleaning wool suits, silk dresses, and other water-sensitive garments. "F" means hydrocarbon solvent only, which is milder than perc and better for garments with delicate trims, coatings, or embellishments. "W" means professional wet cleaning (water-based cleaning with specialized professional equipment that controls temperature, agitation, and drying precisely). An X through the circle means do not dry clean. This is rare but appears on some garments with coatings, adhesives, or treatments that dissolve in dry cleaning solvents. Rubber-backed fabrics, some waterproof membranes, and garments with PVC or vinyl details fall into this category. Underlines beneath the circle indicate cleaning intensity: one line means mild process (shorter cycle, reduced mechanical action, lower temperature), two lines mean very mild process. These restrictions exist for delicate fabrics, beaded garments, and items with fragile construction. When you bring a garment to a dry cleaner, point out the care label and any specific concerns about trims or embellishments. ## Fiber Types and Their Care Requirements Understanding fiber properties helps you interpret care labels intelligently. Cotton is strong when wet (it actually gains 10 to 20 percent strength when wet), tolerates high heat washing and ironing, but shrinks 3 to 5 percent on first wash if not pre-shrunk. Wash cotton at the labeled temperature and tumble dry on medium if allowed. Pre-shrunk or "sanforized" cotton has been treated to minimize shrinkage to under 1 percent. Wool felts (fibers permanently tangle and shrink) in hot water and agitation. The surface of wool fibers is covered in microscopic scales. Heat and mechanical action cause these scales to interlock irreversibly, creating a denser, smaller fabric. This is felting. Always wash wool in cold water with minimal agitation or dry clean. Never tumble dry wool. Lay flat to dry. Use a wool-specific detergent with a neutral pH because alkaline detergents (regular laundry soap) damage wool fibers. Silk is a protein fiber that weakens when wet, losing up to 20 percent of its strength. Hand wash in cold water with a pH-neutral detergent. Do not wring. Roll in a towel to remove excess water and dry flat or hang in shade. Silk is also sensitive to alcohol, perfume, and deodorant. Apply these products before dressing to avoid permanent stains. Polyester resists shrinkage and wrinkling but picks up odors and oil stains that water alone cannot remove. The hydrophobic nature of polyester means it repels water but attracts oils and body odor compounds. Wash polyester in warm water (40 degrees). Tumble dry on low. High heat causes permanent creasing in polyester that no amount of ironing can fix. Adding white vinegar to the rinse cycle helps release trapped odors. Linen wrinkles aggressively because linen fibers have very low elasticity. Wash in warm water, hang to dry, and iron while slightly damp on high heat. Linen gets softer with each wash, so do not over-treat it with fabric softeners that coat fibers and reduce absorbency. Linen is the strongest natural fiber and lasts for decades with proper care. Spandex and elastane (Lycra) lose stretch when exposed to heat, chlorine bleach, and fabric softener. Wash in cold water on a gentle cycle, skip the dryer, and avoid bleach to maintain elasticity. Replace athletic wear and swimwear when the elastic no longer recovers its shape after stretching. Nylon is strong and abrasion-resistant but melts at relatively low temperatures. Wash in warm water and tumble dry on low or hang to dry. Nylon dries very quickly, so machine drying is often unnecessary. Keep nylon away from direct heat sources like radiators. ## Common Mistakes and How to Avoid Them Overloading the washing machine prevents proper water circulation and detergent distribution. Fill the drum to 75% capacity for normal loads and 50% for bulky items like comforters and jackets. An overloaded machine also puts excessive stress on bearings and the suspension, shortening the appliance's lifespan. Sorting only by color is incomplete. Sort by fabric weight, fiber type, and care requirements as well. Washing heavy jeans with lightweight silk blouses damages the silk through abrasion. Washing towels with synthetic activewear transfers lint from the towels to the smooth synthetic surface. Zippers and hooks catch on delicate fabrics, so close all zippers and hooks before washing or use mesh laundry bags. Using too much detergent leaves residue in fabric, attracts more dirt, irritates skin, and creates excess suds that reduce mechanical cleaning action. Follow the dosage instructions on the detergent packaging and reduce the amount by half for soft water. Hard water requires more detergent because minerals bind with surfactants, reducing cleaning power. If you have hard water, consider a water softener or a detergent formulated for hard water. Drying clothes on wire hangers causes shoulder bumps in knitted garments. Use padded or contoured hangers for sweaters and structured garments. Better yet, fold knitwear and store it flat. This tool provides a visual reference for every ISO 3758 care symbol with plain-language explanations. Search by symbol category or browse the complete chart to decode any care label you encounter.
Frequently asked questions
What does the circle in a square mean?
That's for the dryer! I'll show you what the dots inside mean for temperature too.
What if my item has no label?
Treat it as delicate. Cold water and air dry is the safest approach.
