5 minute read

Stone-Rumbled™️ is a new mono-material surface finish for light fittings. It’s 100% environmentally sustainable and was developed through our work on closed-loop Circular Economy.

Stone-Rumbled™️ spotlight - our biggest selling product by volume

It's not a secret that most paints, powder coatings, clear top coats and the like (especially the industrial coatings found on architectural lighting) contain chemicals that are harmful to humans and the environment - product safety warnings are a legal requirement of the product packaging itself.

From acetone and arsenic to xylene and zirconium, the list of ingredients and their negative health consequences is a long one. Taking cancer alone as an example, a percentage of standard ingredients used in paint are already WHO / IARC Group 1 or Group 2A listed carcinogenic.

The product life cycle of coatings begins in the factories where they’re made and applied to products. ‘Coated’ products subsequently live on in the built environment in our homes, places of work, entertainment etc. where the chemistry has consequences on human-health.

Architects, interior designers and building engineers are becoming more conscious of this. If you work on projects that conform to next-generation building codes such as BREEAM, WELL, LEED, SKA, etc. you're probably already dealing with other specifics such as VOC (volatile organic compound) off-gassing and their associated health risks.

What’s less well known is that coatings are also terrible for the environment, for example, they are so common and contain such high quantities of the wrong kinds of plastics that Swiss scientists [¹] have highlighted their potential as the single biggest source of ocean microplastics 🤯.

Stone-Rumbled™️ speaks directly to this growing awareness of product chemistry and the harm it can cause. Getting rid of unnecessary coatings altogether is a simple, cost-effective solution that most clients find easy to understand and accept. 


How does Stone-Rumbled™️ work?

Components are vibrated in a tank of ‘stones’ with water and a special type of soap. This creates low-frequency abrasion which in turn produces an attractive matte surface texture.

The ‘stones’ are actually a very consistent and hard synthetic media. The tank is activated using the same ‘Eccentric Rotating Mass’ or ERM principles found in vibrating sex toys and smart phones, but on a much larger scale - the motor and weight mechanism alone weigh nearly half a ton.

‘Stone Rumbling’ is an electromechanical wet process, so it’s not compatible with regular steel (which would rust). This is why all Factorylux products are upgraded to aluminium. 


The process is ‘subtractive’ like polishing, not ‘additive’ like paint. It works by removing an infinitesimal amount of surface material and doesn’t add anything at all - no plastics, no chemicals, no VOCs, no pollution. It's also notably energy-efficient - York University have used it as a case study for MSc environmental science dissertations.

Stone-Rumbled™️ is proven on many projects in Europe, North America, Japan and the UAE, view the Lookbooks. It’s a totally viable alternative to the paint and powder coatings of standard architectural lighting.

So, why choose it for your project?

  1. Not harmful. Stone-Rumbled™️ works differently to conventional finishes. There’s no harmful chemistry because there’s no chemistry at all. Components are environmentally neutral because they remain as mono-materials. The original substrate (aluminium) is maintained in its pure form, nothing is added, no new multi-materials or composites are created.

  2. Best in class for Re-use. The absence of chemistry is what enables a breakthrough in closed-loop reuse. It means the products we make can be returned to us, dismantled down to mono-material components and reprocessed (‘re-rumbled’) in our factory at a fraction of the cost, energy and pollution compared to raw materials. Even at microscopic level, there is zero measurable difference between ‘processed’ or ‘re-processed’ parts. Stone-Rumbled™️ is 'fresh out of the box' every time.

  3. Lower Price. Stone-Rumbled™️ is cost-effective compared to every alternative surface coating. Clients expect to ‘pay a little more’ for superior environmental performance, but in this example, it’s actually less 🤑.

  4. Looks great. Stone-Rumbled ™️ lighting looks good and feels great. This is very important because however good the environmental performance is, Factorylux can only change the world when our lights and lighting track get specified. Raw metal has a rich cultural history, from wartime planes to post-war kitchens to airstream caravans, coins, jewellery, cutlery, DeLorean cars even - it really can take us back to a better future.

  5. Scale. We developed and finessed the process using a small machine that was limited to small components. Once we established proof of concept we scaled up to a large format ERM machine that had been originally commissioned by Rolls-Royce aerospace. This machine can accommodate our biggest products, such as Reflekter ™️ XL (500mm diameter).



Closed-loop Circular Economy

Painted substrates are ‘composites’ or 'multi-materials', which is the worst case scenario for reuse. At product end of life, a small percentage of them might find 'second users', but many more go directly to landfill.

Coatings on any product that is processed through 'open loop' recycling, such as WEEE in the UK / EU (eg. any paint on high-value, easy to extract metals like steel) will be released as 'dross' - solid waste within molten metal or burn-off as gas.

It’s easy to forget that nothing ever disappears. According to the laws of science, physical 'stuff' can only either a) stay the same or b) become something different. In each scenario, the outcome is the same: what began life as ‘fun and colourful’ coatings, break down according to their fundamental (normally toxic) chemistry and enter humans or the environment as gases, liquids or solids. 

Stone-Rumbled™️ is the sustainable alternative that makes it possible to get rid of coatings before they get rid of us. 

 “The mass in an isolated system can neither be created nor be destroyed
but can be transformed from one form to another”

- Antoine Lavoisier (chemist) 1743-1794


  • [1]
  • Report: 'Plastic Paints the Environment'
  • Authors: Dr Paola Paruta, Dr Margherita Pucino, Dr Julien Boucher.
  • ISBN: 978-2-8399-3494-7
  • ©2021 EA– Environmental Action, Lausanne, Switzerland
  • Download the report (free)

Our stories:


1 - About us 

  • How we got started.

2 - Closed-loop Circular Economy 

  • The how and why of our manufacturing methodology.

3 - Stone-Rumbled™ (you are here!)

  • The most sustainable surface finish ever - explained.

4 - Make-Unmake™

  • Mono-materials are what make a closed-loop possible.

5 - Magic-Packaging™

  • Measure everything that leaves a factory, not just the product.

6 - Magic-Paint™

  • Don't read this if you want to continue using regular paint.

7 - Factorylux Mission

  • Why we exist. Where we are going.