Seamless underwear, bamboo, and merino wool should be washed at low temperatures (30°C or hand wash), with a mild detergent, without aggressive fabric softener, and without a dryer. Air drying, flat and away from direct heat sources, is the step that best protects the shape and fibers of these fabrics.
Why do seamless underwear and delicate fabrics need to be washed differently from other garments?
Seamless underwear is made without side seams, with stretchy microfiber that loses elasticity if exposed to high temperatures or excessive rubbing. Bamboo is a soft but delicate natural fiber, while merino wool has a protein structure that can felt if washed in water that is too hot or with intense mechanical movements. In all three cases, the main enemy is not washing itself, but heat and friction: respecting the correct temperature and program extends the life of the garment and maintains its fit and support.
How to wash seamless and microfiber underwear?
Wash seamless underwear at 30°C, by hand or in the washing machine on a delicate program, enclosed in a laundry bag to prevent it from deforming or snagging with other garments. Use a neutral detergent, avoid bleach, and limit fabric softener, which over time weighs down elasticized fibers and reduces their elasticity. Do not wring: gently press out excess water and lay the garment flat to dry, never hanging, to prevent the weight of the water from deforming its shape.
How to wash bamboo underwear without damaging it?
Bamboo is preferably washed by hand or in the washing machine at 30°C on a delicate cycle, always with neutral detergents free of optical brighteners. It is a fiber that absorbs moisture well but loses softness if exposed to high temperatures or tumble drying: it is better to air dry it, away from direct sunlight which can alter its color over time. In this case, too, a laundry bag protects the fabric from rubbing against rougher garments, such as jeans or sweatshirts.
How to wash merino wool without felting it?
Merino wool should be washed by hand or in the washing machine on a wool program at 30°C, never at higher temperatures: the thermal shock between hot water and cold rinse is the most common cause of felting. Use a specific detergent for wool, avoid rubbing or twisting the garment, and never use a dryer. After washing, lay the garment flat on a towel, shaping it to its original form: hanging a wet merino wool garment will permanently stretch it due to the weight of the water.
Material by material: quick washing guide
| Material | Temperature and wash | Drying |
|---|---|---|
| Seamless / microfiber | 30°C, hand or delicate machine wash, laundry bag | Air dry, flat, never tumble dry |
| Bamboo | 30°C, hand or delicate machine wash, neutral detergent | Air dry, away from direct sunlight |
| Merino wool | 30°C, wool program or hand wash, specific detergent | Flat on a towel, never hung |
What mistakes to avoid to prevent damaging delicate underwear?
The most common mistakes are washing at too high temperatures, using too much fabric softener, wringing forcefully, and tumble drying or direct sunlight. Mixing delicate garments with jeans, sweatshirts, or items with hooks and fasteners also increases the risk of fraying and small tears: a laundry bag solves most of these problems with a simple gesture. For shapewear, such as high-waisted shaping garments, also avoid excessively hot water, which can reduce the elasticity of compression fibers.
These precautions apply to all Risalti underwear lines: the Women's Thermal Leggings in Merino Wool maintain their thermal comfort only if washed at low temperatures and air-dried flat; the High-Waisted Shaping Panty retains its elastic support if it avoids tumble drying and high temperatures; the Classic Soft Touch Bamboo Briefs remain soft for a long time with gentle washing and neutral detergents. You can find the entire selection in the Women's Thermal Underwear collection, the Women's Shapewear collection, and the Women's Bamboo Underwear collection.
To learn more about the characteristics of these materials before purchasing, also read Thermal Underwear: Complete Guide and How to Choose and Bamboo Underwear: Benefits, Comfort, and Sustainability.
Frequently Asked Questions about washing delicate underwear
Can I machine wash seamless underwear?
Yes, but with a delicate program at 30°C and enclosed in a laundry bag, to protect elasticized fibers from rubbing against other garments.
Should merino wool be hand-washed or machine-washed?
Both options are fine, provided you use water at 30°C and, in the washing machine, the wool program with reduced spin; the important thing is never to exceed this temperature to avoid felting.
Can I use fabric softener on bamboo underwear?
It's best to avoid it or limit it: fabric softener weighs down the natural fibers of bamboo and over time reduces its softness and breathability.
Why shouldn't I put delicate underwear in the dryer?
The heat of the dryer deforms the elastic fibers of seamless items, felts merino wool, and excessively dries bamboo: air drying flat is always the safest choice.
With a few extra precautions when washing, seamless underwear, bamboo, and merino wool maintain comfort, elasticity, and support for a long time. A delicate cycle, the right temperature, and air drying are often enough to make these garments last much longer.
