The Science of Gloss Paint Explained

Updated May 11, 2024 | Posted Jan 25, 2022 | Professional insight, Product Advice | 7 comments

As a decorator, I’m forever being questioned about why oil-based products yellow over time and the science of gloss paint. Things have changed dramatically over the past decade, and it doesn’t look as though the rate of change is going to slow.

But what is driving the change? Why does modern oil-based gloss turn yellow? What is the alternative? There are loads of different things in play that are shaping the landscape when it comes to gloss. I thought I’d put a little blog together and explain what’s going on.


The Science of Gloss Paint


Up until 2010, there was only really one type of gloss paint product you would have used, and that was oil-based. The problem is, the oil in oil-based gloss is an alkyd, and one of the properties of alkyds is they turn yellow over time.

Manufacturers used to use chemicals known as VOCs to slow the yellowing process of alkyd oils. However, in 2010 the EU started to restrict the use of VOCs in a bid to make paint more environmentally friendly. The knock-on effect is alkyd products now turn yellow a lot faster than they used to. These restrictions have systematically been tightened since then.

This affects white oil-based gloss more than tinted colours. However, the discolouration happens to some extent in EVERY colour.

So, what is the alternative?

Water-Based Gloss


Well, there is water-based, but this also comes with issues. There are plenty of great quality water-based satinwood products out there, WRX satinwood as an example, is awesome. Water-based gloss is a little trickier. You can’t get the sheen level with water-based, as the sheen would be provided by the alkyd in traditional paints. Water-based gloss doesn’t level off either. You can be left with stringy, horrible brush marks in a lot of cases.

I know water-based technology is getting better all the time as science advances, but it really isn’t there yet.


Hybrid Gloss Paints


Hybrid paint is the answer for me!! This is a technology which isn’t often spoken about. In fact, for reasons that are lost on me, paint manufacturers try to disguise hybrid products as “water-based”. This is a madness!!

Hybrid gloss is what a chemist might call an “alkyd emulsion”. It does contain a very small amount of the alkyd oil, but a lot. Certainly nowhere near the amount that you’d find in traditional oil-based gloss.


The best way I can describe a hybrid gloss is a compromise between water-based and oil-based. I’ll explain.

A hybrid gloss is mostly water-based, but with an “oil carrier”.

A hybrid gloss will level off better than water-based, but not quite as good as oil.

A hybrid gloss will yellow over time, but it will take years for this to happen.

A hybrid paint is tougher than water-based, but not quite as tough as oil.

Get the idea?

In other words, you almost avoid the issue of your gloss yellowing altogether, but without the many drawbacks of fully water-based paint.

Great examples of quality hybrid gloss paints include Teknos Futura and Johnstone’s Aqua.


What Does the Future Hold for Gloss Paint?


Gloss paint products have changed so much in recent years and the evolution of gloss hasn’t finished just yet. We are being driven by legislation and science. The same way as we are being turned away from diesel vans and pushed towards electric.

Change needs to happen because the world we live in is not sustainable. Oil-based paint products will be phased out before long. I just hope the products we are left with will perform as they need to.

Updated May 11, 2024 | Posted Jan 25, 2022 | 7 comments

About the Author

About the Author

Mike Cupit has been in the decorating industry since 2002 and has mostly worked as a Trade Decorator in the domestic sector (peoples’ homes). Self-proclaimed “product geek”, Mike has a passion for paint and decorating tools. Mike now spends most of his time testing paint products and tools, comparing them to similar products on the market, and blogging about the industry in general.


  1. Nic Harrison

    Great read mate. Explains it perfectly and nice and simple in the best way possible

  2. Gordon McWhinnie

    As an apprentice 33 years ago I was informed by college lecturers oil paints will be gone within 10 years. Just not good enough replacements for this to have happened yet

  3. John Langston

    There is always room in the mkt for a fast drying paint but with 40+ years in the trade I find that water based paints are a poor substitute for solvent based paint …. I also find preference is all down to how & when you were trained as a painter… Water based paints are the preferred choice of the younger generation as water based are what they are trained on where as painters like myself were trained on solvent based paints

    • Vince Robinson

      I was trained with oils back in the 80s but I’m mostly water based.

      If you were comparing waterbased to oils pre 2010, I’d agree that oils are better, but they’ve been messed with so much that they’re not the same.

      My apprentice finished his training in 2009 and knew only oils for trim. He did a year in New Zealand and those lads used nothing but WB finishes, inside and out. I’m not ashamed to admit he imparted some of his new skills and tips onto me, and my application skills are better for it.

      It’s just about prep and application at the end of the day. Condition it to suit yourself, pile it on with a quality synthetic brush and leave it, apart from checking, to self level.

      Not telling anyone how to suck eggs, but we all have to be adaptable because the trade changes so much. Experience and skill have a new partner – product knowledge. 👍


    It is a good explanation Nic as you say but as for John and Gordon’s comments for there not being any good enough or are a poor substitute can only be put down to your inability to go out there and find out about waterbased products to replace the oil based products you are still using. “This is the way I’ve always done it” is the usual nonsense you hear from people in this trade or like John says ‘waterbased are for the younger generation because that’s what they were trained on’ is utter rubbish. I started in 1986, I’m fully waterbased and so are plenty of others. I would stop producing oil based tomorrow and do the planet a favour. Time for another round of dinosaurs to become extinct.

    • Vince Robinson

      Gareth. I’ve recently had an ex employee helping me out. He’s been out of the game for a couple of years due to Ill health. Cracking decorator but used to oils.

      He’s been really impressed with the WB we use, particularly the Helmi & Everal trim paints, and that’s just 2 products from many. 😳

  5. Vince Robinson

    I’ve explained the gloss changes to so many customers since. VOC 2010, only to watch their eyes glaze over 🙄.

    Thankfully we’re not asked for gloss very often, but on the odd occasion we are we use oil in the shape of Crown Next Generation +. It’s the closest I’ve found to the old glosses for staying white and application.

    I don’t mind the water based gloss, but one adhesion primer and two top coats let’s it down for me.

    Thankfully most of todays customers like satin or eggshell 👍


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