Bio-based foam: the technology behind the Clovis Bio
With the Clovis Bio 2027 edition, we're moving to a new bio-based foam made from natural rubber. It's an alternative to conventional neoprene that we chose first and foremost for its performance: flexibility, warmth and low weight. Here's what's in it, how it's made, and what it isn't.
Why look for an alternative to neoprene?
Neoprene (polychloroprene) has been the reference material for wetsuits for over 60 years. It insulates well, it's stretchy and it lasts. But it comes either from petroleum, or from limestone in the case of limestone neoprenes such as our Yamamoto neoprene. Either way, these are resources extracted from the ground, and processing limestone takes a lot of energy.
For the past few years, foam manufacturers have been working on another route: replacing part of the fossil and mineral content with renewable resources, starting with natural rubber. Our condition for adopting it was simple: no compromise on warmth or freedom of movement.
What's in the foam
The Clovis Bio foam combines four main resources:
- Natural rubber (hevea): the main ingredient. The latex is tapped by hand from the bark of hevea trees, then coagulated and dried into blocks. It brings the stretch and the comfort.
- Oyster shell powder: sourced from food consumption, the shells are ground, calcined and finely sieved. This powder replaces quarried limestone to give the foam its structure.
- Vegetable oils: they soften the foam, in place of petroleum-based plasticisers.
- Tea stalk powder: an agricultural residue from tea production, ground and put back into the mix.
At Saint Jacques, we know a thing or two about shells: our name and our logo come from the scallop shell. Finding oyster shells at the heart of our new foam felt almost inevitable.
How it's made
Production follows the same main steps as a neoprene foam, with different ingredients:
- Material preparation: natural rubber blocks on one side, shell and tea stalk powders on the other.
- Mixing and foaming: the ingredients are blended, then expanded to create a closed-cell foam that traps air and insulates against the cold.
- Slicing into sheets: the foam blocks are cut to the required thickness (3 mm, 4 mm…).
- Laminating: the sheets are backed with fabric on both faces before the wetsuit is assembled.
What about performance?
That was our priority. Natural rubber offers genuine stretch and a soft feel. Its closed-cell structure delivers solid thermal insulation, and its low density makes for a lightweight foam.
The foam exceeds 380% elongation at break (ASTM D412) and remains dimensionally stable after heat exposure.
On the Clovis Bio, this foam is paired with:
- the FLASH thermal lining from chest to knees;
- glued and blind-stitched (GBS) seams, taped on the inside;
- liquid seal cuffs and ankles.
The result: a winter fullsuit as warm and as stretchy as our neoprene models.
Certification and testing
The foam is certified as a USDA Certified Biobased Product. This US Department of Agriculture programme measures, in the lab, the share of a material's carbon that comes from renewable sources, following the ASTM D6866 standard.
According to our supplier, the foam also complies with REACH requirements and with testing for heavy metals, phthalates and PAHs (polycyclic aromatic hydrocarbons).
What this foam isn't
We'd rather be clear, because this subject lends itself easily to greenwashing:
- The wetsuit isn't 100% bio. The foam is bio-based, but the lining fabrics, thread, glue and zip are still synthetic.
- The foam isn't entirely plant-based: it contains a small share of other components needed to hold it together.
- It isn't biodegradable and should never be discarded in nature.
For us, the most effective approach is still to build wetsuits that last, then give them a second life through our Neocycle project.
Neoprene vs bio-based foam
| Petroleum-based neoprene | Limestone neoprene | Bio-based foam | |
|---|---|---|---|
| Base material | Petroleum | Limestone | Natural rubber, oyster shells, vegetable oils, tea stalks |
| Resource | Fossil | Extracted mineral | Mostly renewable |
| Stretch | Varies with quality | Very good | Very good |
| Bio-based certification | No | No | USDA Certified Biobased |
| At Saint Jacques | Not used | Yamamoto and Limestone Superstretch ranges | Clovis Bio 2027 |
The Clovis Bio 2027 edition
The first wetsuit to use this foam is the Clovis Bio. It's a winter chest zip fullsuit, available in 3/2 and 4/3, with:
- a completely new pattern, with no pressure points;
- a blue burgundy colourway with a Breton stripe detail;
- a design built for surfing, wing foiling, kitesurfing, windsurfing, SUP and open water swimming.
Frequently asked questions
Is the Clovis Bio made of neoprene?
No. Its foam is based on natural rubber, an alternative to conventional neoprene, whether petroleum-based or limestone.
Is a bio-based foam as warm as neoprene?
Yes. The closed-cell structure insulates in the same way, and the FLASH lining adds warmth. At equal thickness you get the same temperature ranges: 16 to 23°C in 3/2, 13 to 20°C in 4/3.
How do I look after it?
Just like a neoprene wetsuit:
- rinse with cool fresh water after every session, inside and out;
- dry flat, in the shade, never on a hanger;
- never tumble dry or use a direct heat source.
We explain it all in our guide: how to wash and care for your neoprene wetsuit.
Where can I find the other Saint Jacques technologies?
All our materials and finishes are detailed on our Technology page.