5 minute read

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


People are becoming more aware that surface coatings (paint, powdercoat, lacquer and so on) generally contain ingredients that are harmful to humans. Taking cancer alone as an example, many of the standard ingredients used in paint are already WHO / IARC listed as Group 1 and Group 2A carcinogenic.

If you work on projects that conform to next-generation building codes such as BREEAM, WELL, LEED, SKA, etc. you're probably already familiar with other specifics such as VOCs (volatile organic compounds) 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, 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 an obvious, cost-effective solution that most clients can easily 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 use 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 Lookbook. It’s a totally viable alternative to the paint and powder coat 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 single materials. The original substrate (aluminium) is maintained in its pure form, nothing is added, no new 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 and reprocessed (‘re-rumbled’) in our own 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'd 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). 


Get a free sample



Notes on regular coatings ☠️ ...

Nearly all paints, powder coatings and such (especially the industrial coatings that you’re likely to find on architectural lighting) contain chemicals that are known to be harmful to humans and the environment. 

This is not a secret - product safety warnings are a legal requirement of the product packaging itself. From carcinogens to brain function, the list of ingredients and their possible health consequences is a long one: from acetone, ammonia, antimony, and arsenic to xylene and zirconium.

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

Closed-loop Circular Economy

Substrates which have been painted become ‘composites’ (meaning: 'more than one material, not easily separated') which is a bad case scenario for closed-loop Circular EconomyAt product end of life, a small percentage might find 'second users', but many more go directly to landfill. 

The coatings on high-value, easy to extract metals like steel that get reprocessed through 'open loop' waste recycling, such as WEEE (Waste Electrical and Electronic Equipment Directive) in the UK / EU, are released as gas or 'dross' (solid waste within molten metal) as they burn-off during the process.

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. Yes folks, it’s that grim. 

“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




  • 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)

The essays:


1 - Introduction 

  • What's it all about

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™

  • Single-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.