What the number in the wash tub means
Short answer: The number in the wash tub is the highest temperature the item may be washed at. It is a ceiling and not a recommendation, so you are welcome to wash colder than it says. Washing hotter risks damage to colour, shape and fabric.
The ceiling protects the fabric
Above the stated temperature the colour can move, the fabric can shrink or the elastic can be damaged. That is why the number is there. It is set from what the fabric and colours can take, and it is the maker's way of telling you where the limit is.
Lower is almost always possible
Washing at twenty degrees instead of forty keeps the colour longer and spares the clothes from heat. It is rarely necessary to go all the way up to the number. See night T-shirts for men and read the label, so you can choose a programme below the limit.
Lines under the tub change the programme
One line under the tub means a gentle wash, and two lines mean very gentle. This is about mechanics, not heat. The machine should run with fewer spins and softer movement. See home and homewear in bamboo and bamboo towels and check what the label says.
A hand in the tub
A hand in the tub means the item is washed by hand and not in the machine. Then lukewarm water and no hard wringing apply. The number is not used in the same way here, because a hand cannot take hot water. Use water that feels comfortable on your skin.
A cross over the tub
A cross over the tub means the item must not be washed in water. That is rare on everyday clothes, but it does happen. Follow the message, and ask the maker if you are unsure. Do not test with a small wash, since damage often shows only afterwards.
Sorting by the number
Put clothes with the same number together, and wash at the lowest number if you mix. Coloured and light clothes do not belong together at high temperature, because colour can bleed. At thirty degrees the risk is smaller. Sort by colour first and then by the number in the tub.
Detergent and temperature go together
A good detergent works at a lower temperature when you use the right amount and a suitable programme. More detergent does not make the laundry cleaner but can leave residue in the fabric. Read the dosing on the pack and adjust it to how dirty the load is.
When hotter makes sense
Washing hotter can be reasonable when clothes are visibly dirty or when something calls for it on hygiene grounds. Always check that the number on the label allows it. If the label allows only thirty degrees, do not go higher, even if you want an extra clean result.
Making it a habit
Look at the number each time before you fill the machine, and choose the programme to match. Most machines have fixed programmes at thirty and forty degrees, so it is easy to get right. After a few times it sticks, and you hardly need to think about it.
Frequently asked questions
Does the laundry get clean at thirty degrees
Yes, with a good detergent in the right amount. For normally worn clothes it is plenty, and it spares fabric, colour and elastic, so the clothes last longer.
When should I wash hotter
When there is visible dirt or when something calls for it on hygiene grounds. Check first that the label allows a higher temperature, because the number always sets the limit.
Can I wash everything at the same temperature
Yes, if you choose the lowest of the temperatures shown on the clothes in the machine. Sort by colour as well, so light items are not affected by dark ones.
You can find the full range at Bamboo-Clothing.com.
