Modal is a semi-synthetic fibre that’s found fame in the age of activewear. But as technological advances continue to introduce a new generation of eco-fabrics, it can be daunting to decipher a garment’s green credibility. Modal is one such fabric.

This cotton alternative is breathable and absorbent. It’s used in the manufacture of underwear, pyjamas, bathrobes, bed sheets and more.

What do we mean by modal?

Modal fibre is the generic name for a semi-synthetic rayon, which was originally developed in Japan in 1951. Today one of the best-known producers of modal is the Austrian company Lenzing AG, who market their version under the name Lenzing Modal®. Lenzing Modal is protected by a global certification system which is registered worldwide.

What is modal and how is it made?

Breathable and silky smooth to the touch, modal is around 50% more water-absorbent per unit volume than cotton. Boasting similar properties to other cellulose fibres, it’s designed to absorb the dye and stay colour-fast when washed in warm water, making it a popular choice in the manufacture of underwear and activewear alike.

With an impressive resistance to shrinkage and pilling, it’s worth noting that modal may be used on its own or in a textile blend. The manufacturing process involves spinning reconstituted cellulose from beech trees. The wood fibres are pulped into liquid form and then forced through tiny holes, creating the fibre. This is then woven together to make the modal fabric.

How does modal impact the environment?

It depends. Lenzing has developed innovative environmental processes for the manufacture of Lenzing Modal which are not commercially available to others. These non-toxic technologies have allowed Lenzing to recover up to 95% of Modal’s production materials, minimizing emissions and conserving resources.

The environmental footprint of Lenzing Modal is a positive one – it’s carbon-neutral, requires less land per tonne than cotton fibres and has a water consumption level that’s ten to twenty times less than that of cotton. Many brands, therefore, see Modal as an eco-friendly choice.

So why then has modal received a lower Class D rating from materials experts Made-By?

Made-By’s widely respected Environmental Benchmark for Fibres ranked fibres for their sustainability impact – Class A have the least negative impact and Class E the most. Whilst the trademarked Lenzing Modal is harvested from sustainably managed beech tree plantations in Austria and surrounding European countries, the origins of other modal fibres on the market are often less transparent, according to the nonprofit Canopy. For example, less reputable manufacturers have been accused by the Rainforest Action Network of forest destruction in Indonesia. According to sustainable fashion commentator Summer Edwards, “modal that has been produced in Indonesia is known to be manufactured with plantation woodstock that is grown in areas of rainforest that have been clear-felled to make way for monocrop timber plantations”.

A key factor in all of this is that Lenzing does not produce ready to wear fabrics. Instead, the company sells yarns to mills and manufacturers who in turn make fabrics. The environmental impact involved in weaving fibres into fabrics can be significant, with conventional methods using high levels of water and chemicals.

How does modal compare to other rayon fabrics?

Modal is often compared to other types of rayon, like viscose or lyocell.

Although the production for modal and viscose are similar, the resulting modal fibres are much stronger (especially when wet), but also lighter and more breathable. What’s more, modal is considered better for the environment than viscose, since less chemicals are needed to produce it.