Frequently Asked Questions
What do the dots on a washing symbol mean?
One dot is 30°C, two dots 40°C, three dots 60°C. They are maximum temperatures, not requirements; washing cooler is always safe.
What does a square with a circle mean?
Tumble dry. The dots inside the circle set the heat level. For socks, air drying is almost always the better choice even when tumble drying is allowed.
What does a crossed-out iron mean on socks?
Do not iron. Heat damages the elastic, and on a grip sock it melts the grip compound permanently.
Can I tumble dry socks if the symbol allows it?
You can, but the elastic and the grip will degrade faster. Air drying extends the life of a sock more than any other single habit.
What does a crossed-out triangle mean?
Do not bleach. Chlorine bleach weakens cotton and fades colour, and it attacks the grip compound.
Care label symbols fall into five groups: wash, bleach, dry, iron and professional cleaning. On a sock, the two that matter most are the wash tub with its temperature dot and the drying symbol, because heat is what destroys the elastic and the grip. The iron symbol is usually crossed out on socks, and on a grip sock it always should be.
The Five Symbol Groups
The international symbol system uses a shape for each group, with modifiers inside or below. Once you know the shape, you know which process the symbol is talking about; the modifiers tell you how much.
| Shape | Group | Modifier |
|---|---|---|
| Washtub | Washing | Dots for temperature, a hand for hand wash, a cross to prohibit |
| Triangle | Bleaching | Empty for any bleach, diagonal lines for non-chlorine only, crossed for none |
| Square | Drying | A circle inside for tumble dry, dots for heat level, a line for line dry |
| Iron | Ironing | Dots for temperature, crossed for do not iron |
| Circle | Professional cleaning | Letters for solvent type, crossed for do not dry clean |
The Wash Tub and Its Dots
The washtub with one dot means a maximum of 30°C, two dots 40°C, three dots 60°C. A washtub with a hand inside means hand wash only. A washtub with a cross means do not wash, which for a sock would be unusual and would point to a specialty product.
For socks, the practical range is 30 to 40°C. A cotton sock with elastane should not go above 40, because the elastane degrades and the cuff loses its grip. A wool sock goes at 30 or by hand. A trampoline park sock knitted from polyester can take more heat but does not need it, because the sweat it absorbs is water-soluble.
The dots are a maximum, not a requirement. Washing cooler than the symbol allows is always safe; washing hotter is what causes the damage.
The Square: Drying Is Where Socks Fail
A square with a circle inside means tumble dry, and the dots inside the circle set the heat. A square with a horizontal line means dry flat; a square with a vertical line means line dry; a square with a curved line at the top means drip dry.
For socks, the tumble dry symbol is the one to treat with suspicion even when it is present. Heat is the single fastest way to destroy the elastic in a cuff and the adhesion of a grip pattern. A sock labelled for tumble drying will survive it once or twice; a sock dried in a tumble dryer every week will lose its shape within a season.
If a sock carries the do-not-tumble-dry symbol, that is not a suggestion. Wool socks felt and shrink permanently, and grip socks lose adhesion at the pattern edges.
The Crossed-Out Iron and the Grip Sock
Most socks carry a crossed-out iron. That is because a sock rarely needs ironing, and because heat damages the elastic. On a grip sock the crossed-out iron is essential: the grip is a cured silicone or PVC compound, and a hot iron will melt or distort it permanently.
If a sock carries an iron with one dot (110°C, no steam), that applies to a flat cotton sock with no elastic and no grip. It is rare in practice.
The Triangle: Bleach
An empty triangle allows any bleach, a triangle with two diagonal lines allows non-chlorine bleach only, and a crossed triangle means no bleach. Most socks carry the crossed triangle, because chlorine bleach weakens cotton and yellows white socks over time, and colour socks lose their dye.
An “oxi” or oxygen booster is not the same as chlorine bleach; it is closer to the non-chlorine symbol. Even so, repeated use dulls colour and stresses the grip compound.
The Circle: Professional Cleaning
The circle with a letter inside refers to the solvent a dry cleaner should use; a crossed circle means do not dry clean. Socks almost never carry a dry-clean instruction, because the processes are designed for tailored garments rather than knitwear.
Where a circle appears on a sock, it is usually to prohibit, not to instruct.
Reading a Real Sock Label
A typical cotton grip sock might carry: washtub with two dots (40°C), crossed triangle (no bleach), square with a line (dry flat), crossed iron (do not iron), crossed circle (do not dry clean). That combination tells the customer everything that matters: wash warm, no bleach, air dry, no heat.
A wool sock might carry: washtub with one dot or a hand (30°C or hand wash), crossed triangle, square with a line (dry flat), crossed iron, crossed circle. A trampoline park sock might allow a warmer wash but will still prohibit the iron.
When you order custom socks, the care symbols belong in the specification alongside the fibre percentages. Our textile labeling guide covers the label as a whole, and our care labeling guide covers the US requirements in more detail.
Why the Symbols Matter Commercially
Care symbols are not decoration. A customer who follows the wrong instruction returns the product, and a sock that has been shrunk or has lost its grip cannot be resold. Publishing the correct symbols, matched to the actual construction, is one of the cheapest ways to reduce returns.
It also protects the brand when a customer claims the product failed. A label that says do not tumble dry, followed by a customer who tumble dried, is a different conversation from a label with no instruction at all.
Every custom packaging sleeve and header card we produce for custom brand socks and private label grip socks includes verified ISO/ASTM care symbols.
Frequently Asked Questions
What do the dots on a washing symbol mean?
One dot is 30°C, two dots 40°C, three dots 60°C. They are maximum temperatures, not requirements; washing cooler is always safe.
What does a square with a circle mean?
Tumble dry. The dots inside the circle set the heat level. For socks, air drying is almost always the better choice even when tumble drying is allowed.
What does a crossed-out iron mean on socks?
Do not iron. Heat damages the elastic, and on a grip sock it melts the grip compound permanently.
Can I tumble dry socks if the symbol allows it?
You can, but the elastic and the grip will degrade faster. Air drying extends the life of a sock more than any other single habit.
What does a crossed-out triangle mean?
Do not bleach. Chlorine bleach weakens cotton and fades colour, and it attacks the grip compound.
Ordering custom socks and need the care symbols matched to the construction? Send us the spec and we will supply the label artwork.