How should TENCEL undershirts be washed and dried?

Short answer: TENCEL is Lenzing's brand for its lyocell and modal fibres, both regenerated cellulose. Undershirts in these fibres are usually machine washable, but how they are washed and dried affects how they look. Lyocell can crease when washed and spun hard, and wet abrasion in a crowded drum can cause fibrillation, a fine fuzz or whitish bloom on the surface, especially on dark colours. A safe default is a gentle or synthetic cycle at a moderate temperature, washing inside out with similar colours, a full but not packed drum, a reduced spin, and line or flat drying or a low tumble setting if testing supports it. Avoid chlorine bleach. Whatever you put on the label must be supported by your own tests on the finished garment, because the fabric construction, dye and finish matter as much as the fibre. In the US, the FTC Care Labeling Rule requires care instructions to be reliable; in Europe care symbols follow ISO 3758 and GINETEX practice.

Common care problems

• Creasing after a hard spin or when left in the drum.
• Fibrillation or a fuzzy, whitish surface on dark shades.
• Shrinkage in length after hot washing or tumble drying.
• Loss of softness when fabric softener builds up.

Suggested care instructions to test

• Machine wash gentle at 30 or 40 °C, inside out.
• Wash with similar colours, do not overload.
• Do not bleach.
• Line or flat dry, or tumble dry low if tests pass.
• Cool iron if needed.

Testing the instructions

Wash finished undershirts following ISO 6330 procedures at the temperature and drying method you plan to put on the label, then check appearance, dimensional change and colour. Repeat for several cycles and compare with an unwashed control. If a garment fails at the planned setting, choose a gentler instruction rather than hoping customers will be careful.

Making a care claim

Lenzing's own materials describe its fibres' softness and moisture properties; use such claims only as allowed under Lenzing's branding rules, and do not claim easy care unless your garment tests support it.

A worked example

As an illustration, a brand could wash dark and light undershirts at 30 and 40 °C with line and tumble drying, then compare surface fuzz and length. If dark shades fuzz at 40 °C with tumble drying, the label can specify 30 °C and line drying.

Limits

Customers do not always follow labels. Choose fabrics and finishes that tolerate some misuse.

Facts, recommendations and uncertainty

Established: lyocell and modal can crease and fibrillate with hard washing. Recommendation: test care instructions on the finished garment and choose gentle settings. Uncertain: how strictly customers will follow them.

Sources and further reading

• Lenzing — TENCEL™ Lyocell and Modal fibers
• ISO 3758:2023 — Care labelling code using symbols
• eCFR — 16 CFR Part 423, Care Labeling of Textile Wearing Apparel
• ISO 6330:2021 — Domestic washing and drying procedures for textile testing

Standards and regulations are referenced by their published scope. Test parameters, cycles and pass levels should be agreed with your laboratory for the specific product; legal requirements should be confirmed for each destination market.