Behind the Fabric: Cellulock

We’ve constantly refined and experimented with the development of our fabrics to meet the ever-changing needs of our customers. Any visit to the Sunspel archive in Long Eaton usually brings up a host of treasures from our ongoing experiments to create fabrics that are not only technical marvels but are also incredibly comfortable against the skin. While some experiments may never go into production, some become new staples that define what we do. This is no truer than in the case of our trademark Cellulock fabric.


Cellulock was an extension of our underwear range – once the mainstay of the business. The fabric was sold as a unique combination of warmth and lightness. The original development was backed in a merino wool as an outer layer, not too dissimilar to our Vintage Wool. As an underlayer our original cellular mesh cotton allowed air to circulate, providing great comfort. Here's how it was described in a 1942 advert for the range:

“The wool outside affords warmth and protection – the cotton cellular weave inside ensures the body can breathe and prevents the wool from irritating sensitive skin.”

The fusing together of the two fabrics was a step forward in the development of our underwear range and came to feature in a number of styles including undershirts and long johns.

When the fabric was discovered in archive garments from the 1950s, we saw an opportunity to revisit this unique fabrication and update it for the present day. We did away with the original wool backing and used jersey on both sides. The double-faced jersey construction means that it is made from two different types of knit – on one side is a tight rib that forms the interior, while the exterior is a textured cellular knit that gives the fabric its unique detail. This gives the construction a lighter feel than the original fabric.

 cellulock labels 

Wearing Cellulock

Sitting somewhere between our Jersey and Loopback sweats in weight, Cellulock is the perfect garment for layering without creating any extra bulk. Designed across a range of grab-and-go styles that nod to sportswear shapes, the virtues of the range lie in its versatility.

The slim cut of the Cellulock sweatshirt makes it ideal for smart and casual looks. Pair it with the matching T-shirt and shorts for a relaxed combination suited to lounging at home or the gym or dress it up with a shirt, jeans and a light jacket as the season transitions to spring.

Shop the Cellulock range