Kneadatite ® Green Stuff –
The Original Formulation Green Modelling Putty
An important update about the future of Kneadatite ® Green Stuff
As of February 2026, Kneadatite Green Stuff is no longer being manufactured in the United States. PPG Industries have permanently closed the PSI production plant in Pennsylvania which supplied model making and industrial maintenance epoxy putty sticks for the global market. If you are looking for Kneadatite Green Stuff, please read this important update about the future of the product.
Kneadatite Green Stuff was originally conceived in the 1970s as a plumbing epoxy putty manufactured in the United States by a company called Polymeric Systems Inc (PSI). Wargamers and other miniature makers soon realised the cut of Green Stuff and its ability to hold intricate details made it perfect for sculpting models. Over the past 50 years, it has become one of the most popular model making putties in the world.
PSI were acquired by PPG Industries in 2019. Production of epoxy putty sticks continued at the PSI factory until 2025, when PPG announced it was closing all operations and withdrawing from the epoxy putty stick market – one of several US companies to do so in response to tariffs.
Tariffs rock the global epoxy putty stick market
US manufacturers of epoxy putty sticks have seen tariffs squeeze them from both ends. The US Department of Commerce imposed anti-dumping duties as high as 355 percent on epoxy resin raw materials imported from China, India, South Korea and Thailand.
At the same time as the cost of raw materials was going up, retaliatory tariffs made exporting finished products out of the US more expensive and challenging than ever. For PPG and other manufacturers, epoxy putty sticks represented only a small portion of their business portfolio. Concluding it was no longer suitably profitable to stay in the market, some of the biggest names left.
The industrial maintenance industry was hit first with serious ramifications to the supply chain. Now the impact has filtered through to the model making industry – and Green Stuff in particular.
Kneadatite ® Green Stuff in Europe
Sylmasta LTD were the first company to introduce Kneadatite Green Stuff to the United Kingdom and European modelling market at Euro Millitaire in Folkestone during the 1990s. Kneadatite Green Stuff has been supplied in Europe by Sylmasta ever since. First under their own name and then SylCreate from 2020 after the business was split into separate brands for industrial maintenance and model making, craft and restoration.
Crucially for the future of Green Stuff, Sylmasta HQ is home to the only epoxy putty stick manufacturing plant in the UK. It currently produces over 15 different epoxy putty stick formulations, including Geomfix Original Modelling Putty – a softer, smoother, more easily-worked version of Milliput.
The investment in the latest epoxy putty stick manufacturing technology means Sylmasta have the machinery to produce their own version of Green Stuff for sale to end-users and distributors worldwide.
A new Green Stuff Modelling Putty
Sylmasta have already begun the process of working on a new Green Stuff formulation compatible with their machinery. They are aiming to make it as close to the original as possible both in chemistry and how Green Stuff is used, although it will be impossible to replicate exactly.
New Green Stuff will be supplied in stick format only in response to issues with the ribbon. Many users complain that where Part A and Part B touch down the middle of the strip, the putty cures before use and is therefore wasted.
Sylmasta intend to sell new Green Stuff as one 50g stick of Yellow Part A and one 50g stick of Yellow Part B packed in a tube. This will not only stop premature hardening but also give users greater control over changing mix ratios from 50-50.
Creating a new formulation for Green Stuff gives Sylmasta a rare opportunity to tweak its properties. They are asking for feedback on what users like and do not like about the original Kneadatite Green Stuff to help guide them in the development process. You can get in contact with Sylmasta by emailing sales@sylmasta.com with your opinion.
Further updates about the progress of new Green Stuff being manufactured and introduced to the market will be announced on the Kneadatite website as and when they happen.