top of page
  • Writer's pictureheykiddoco

What is Jesmonite AC100?

Updated: May 6, 2021

Jesmonite is an incredibly versatile, strong composite material, formed from a reactive raw mineral powder base combined with a water-based acrylic resin. Hailed as a chameleon material, it can quite accurately mimic many surfaces, textures and colours, from stone, wood to metal and more. It is available in many different forms and grades, depending on its desired use.

Specifically regarding homewares, Jesmonite AC100 is the composite of choice. It's incredibly easy to cast and has the ability to replicate micro details within moulded surfaces. It has a creamy viscosity once mixed, making it very easy to pour into small moulds and can be easily pigmented to almost any colour.

Two mixing bowls containing Jesmonite AC100 liquid and powder

What is Jesmonite made from?

It's tricky to hunt down the specific ingredients of what Jesmonite is made from. The main headline is, it's a 'mineral base powder and a pure water-based acrylic resin'.

Snippet from the Jesmonite website: "What are Jesmonite products made from? Jesmonite products are composite materials, a combination of a reactive mineral base and a pure water based acrylic resin."

It's a 1-part liquid resin to a 2.5-part mineral powder mix. Once combined the chemical reaction bonds the two materials into a completely solid surface. The process is quick, taking around 20 minutes to bond - though I would heavily recommend leaving to set for at least 2 hours before removing from a mould and a full 24 hours to fully cure.

What is modified gypsum?

The powdered component of Jesmonite is a modified gypsum. Gypsum is a mineral consisting of hydrated calcium sulphate. It is typically white and has a soft chalky texture. It is a non-toxic, non-hazardous material that naturally occurs within sedimentary rocks.

Gypsum is the most common sulphate material. While naturally occurring, it can also be formed by removing oxygen, allowing sulphur, calcium and water to bond and create gypsum.

So, what does the modified part mean? Modifying a material typically means that the product has been altered in some way to make it more useful or suitable for its production. This could be the way in which gypsum is mined or produced, or a process after the fact that alters its state. The process for Jesmonite is not specifically outlined, though it is a common practice within many industries to alter raw materials to make them more useful.

Close-up of Jesmonite AC100 powder. It is peachy-white in colour.

What is an acrylic resin?

The liquid component of Jesmonite consists of a water-based acrylic resin. Acrylic is widely used in manufacturing and is more of an umbrella term for petroleum-based thermoplastics. It is versatile and strong material, which, once in a solidified form, becomes very robust.

Since Jesmonite qualifies as an eco-resin and not a bio-resin, we can assume that the resin component is synthetic; a plastic, non-biodegradable material constructed from fossil fuels. As Jesmonite is water-based, the main ingredient for the resin is water.


What does eco-friendly mean in the context of Jesmonite?

Knowing that one of the main components of Jesmonite is plastic, how does it qualify as eco-friendly or an eco-resin? Relatively speaking, it absolutely is.

The manufacturing methods behind Jesmonite means it is produced in an extremely sustainable way. Particularly the gypsum component; a naturally occurring material that can be found in abundance and a much greener alternative to fiberglass and concrete. With gypsum sites here in the United Kingdom, the import-export chain to move gypsum to manufacturing facilities is minimal, massively reducing the environmental impact on haulage.

However, the concerning component is the acrylic plastic. This is a double-edged sword, it will not decompose and may release harmful chemicals into the environment, i.e. microplastics from the sanded Jesmonite surfaces or erosion over time. However, the other edge of the sword highlights that, since acrylic is highly durable, products are designed to last. This includes building materials, sculptures and homewares. Responsible product manufacturers and consumers can find a nice equilibrium in Jesmonite: a material designed to last and combat fast fashion.

What's the difference between eco-resins and bio-resins?

Referring to a product as eco-friendly or a greener alternative can often be confusing labels. As we have discussed above, Jesmonite does have some greener, eco-friendlier components. It can be considered greenwashing when using the umbrella term 'eco-friendly'. This term is often misunderstood as being good for the environment, and can fail to tell the whole story of what a product contains.

An eco-resin is a term used for resins that are non-toxic and water-based. The important quality here is that these eco-resins do not output toxic chemicals into our environment or directly affect health.

A bio-resin includes all of the benefits of an eco-resin, but is derived completely from natural and renewable materials. It has no synthetic components and is made from all-natural ingredients.

Therefore, when referring to the environmental safety of Jesmonite, there are a few other benefits to consider: it's water-based, solvent-free and no-VOC's.

Snippet from the Jesmonite website: "Are Jesmonite products safe? All Jesmonite products are water-based, non-solvent and contain no VOC's."

What does water-based mean?

There are typically two types of base components for liquid materials; water-based and oil-based. This means that either water or oil is the main ingredient of the product. When the product dries or cures, the liquid component evaporates, leaving only the solid material behind.

This process can produce volatile chemicals in the form of VOC's (Volatile Organic Compounds). These vapours can be toxic, harmful, affecting both the environment and human health.

With water-based, solvent-free procuts, they do not release harmful chemicals when dried and the water evaporates.

What does solvent-free mean?

Solvent-free and water-based are closely linked. The liquid component of Jesmonite is water-based which doesn't feature any solvents and therefore does not release toxic chemicals into the environment whilst curing.

What does no-VOC's mean?

VOC's stands for Volatile Organic Compounds. These are harmful chemicals that are released in the form of vapours during the drying process. As Jesmonite is water-based and solvent-free, it will not release harmful, toxic chemicals whilst the powder and liquid are reacting.


Jesmonite AC100 and Sustainable Homewares

Given the qualities of Jesmonite we have established above, we can ascertain the following:

✔ Sustainable natural gypsum base

✔ Sustainable manufacturing processes

✔ Durable and hard wearing material

✔ Water-based

✔ Solvent-free

✔ No-VOCs

The main drawback to Jesmonite is its acrylic polymer liquid component. However, it is important to highlight that this is an essential part to making the material as versatile and resilient as it is, allowing for the creation of higher quality products.

Without Jesmonite, creators would have to use far inferior and less-environmental materials to create products. Overall, this makes Jesmonite one of the most environmentally-conscious products on the market, allowing for creative-freedom and resulting in longer-lasting products.

Responsibility as Creators

As someone who uses Jesmonite regularly, I also have a responsibility to improve my practices, to be overall more environmentally friendly. This can include:

  1. Repurposing any waste material left over from Jesmonite castings

  2. Remaking any broken or unsuccessful Jesmonite castings into something new

  3. Reusing any buckets, sheeting, general materials when mixing and pouring Jesmonite

  4. Ensuring any waste water is correctly filtered and disposed of

  5. Not allowing any waste material, when working with Jesmonite, to enter the environment (waste water, sanding particles etc.)

  6. Reduce, reuse, repurpose, recycle


Citizen Sustainable, Is Jesmonite Sustainable? (What You Should Know)

Casting About, What Are Eco-Resins?



bottom of page