How to wash underwear so it lasts
lingerie is more durable than it looks, but nylon-elastane blends have specific enemies: heat, friction, and certain detergents. A few consistent habits make a significant difference to how long a piece holds its shape and softness.
Temperature is the main variable
Elastane fibres begin to degrade at temperatures above 40 degrees Celsius. Washing at 30 degrees is the safest option for maintaining stretch recovery over time. Hot washes. Anything above 60 degrees. Will cause the elastane to lose its memory faster, meaning the waistband and leg openings will start to sag after fewer wears.
Tumble drying is the fastest way to shorten the life of underwear. The combination of heat and mechanical agitation breaks down elastane fibres at a rate that hand-washing or machine-washing at 30 degrees does not. Air drying, either flat or hung, is the correct method.
Mesh bags and gentle cycles
A mesh laundry bag protects pieces from friction with heavier items in the drum. Denim, towels, anything with a rough surface. The bag also prevents straps and edges from catching on machine drum holes, which can cause snags in the knit structure.
Use a gentle or delicate cycle rather than a standard cotton cycle. The reduced agitation is more important than the temperature setting for preserving the knit structure.
Detergent and storage
Avoid detergents with optical brighteners, which can affect the colour of darker pieces over time. A small amount of standard liquid detergent is sufficient. Fabric softener is not necessary and can leave a residue that reduces the fabric's moisture-wicking properties.
Store pieces folded rather than rolled. Rolling can stretch the waistband over time if the piece is stored tightly. A flat fold takes up slightly more drawer space but keeps the waistband in its original shape.
These are not complicated habits. The main ones are: 30 degrees, mesh bag, no tumble dryer. Everything else is secondary.