Let's Get Technical: Mercerised Cotton

A majority of sock brands construct their product using basic combed cotton, but for Fortis Green, the choice was simple: our cotton must be mercerised. While a large portion of our buyers are aware that mercerised cotton is superior, we've had several queries asking about the whys and wherefore's behind our choice.

The practice of mercerising cotton involves expanding newly harvested cotton through a series of solution washes before it is dyed and spun - a technique invented as far back as 1844. The resulting fibres become stronger, more durable and more capable of taking on dye. While the resulting yarn has unrivalled colour saturation and a lustrous appearance, more importantly, the expanded mercerised fibres will then not shrink or fade. We have also taken the optional last step of 'gassing the thread'. In this process the thread passes over an open flame, incinerating stray fibres. The result is a finished sock that will never pill.

But before our cotton even arrives in Italy for processing, we have to go back to basics – where is our cotton grown and what quality of cotton will these plants ultimately yield.

The Egyptian cotton Fortis Green has utilised for our sock production has a longer fibre than regular cotton, allowing for fewer splices when spinning. Quality cotton dress socks must begin with fine cotton, and the ultimate quality of the cotton depends on the length of the individual fibres, or ‘staples’. The extra long-staple specie of Gossypium barbadense (Sea Island cotton) is very demanding in terms of irrigation and climatic conditions, only growing in a few countries such as Egypt. This is why this high quality crop accounts for just 15% of the world’s cotton production and as it is still picked by hand, we are proud to say our cotton has not been harvested using the harmful chemical defoliants utilised by mechanical harvesting methods common in large-scale commercial cotton production.

Our delicate raw cotton bolls are then shipped to a highly esteemed cotton mill in Italy. It's then up to the expertise of the spinner, along with the technologies used throughout the processing cycle that will mark the final quality the yarn spun.

Fortis Green’s cotton yarn is dyed with colorants that meet the human and environmental standards established by the OEKO-TEX Standard 100. This is an independent international testing and certification system for textiles at all stages of production. The more intensive the skin contact of a product, the stricter the requirements and the dyes used by our chosen mill meet the highest class level of Grade 1.

From traditional manual harvesting to the best of modern technology, Fortis Green’s cotton then undergoes one last unique process. We have employed Swiss textile technology company HeiQ to pre-wash our yarn in order to provide a sock with an unrivalled super soft finish.

All of these steps take place before our cotton has even arrived in Portugal where our socks are knitted and finished. It’s this level of attention to the fundamental materials that go into the making of our product that makes Fortis Green socks absolutely top drawer.

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