If you’ve ever seen tyre decals turning brown or developing patches over time, you might assume the material has failed. That’s not the case. This is a side effect of tyre chemistry, not the decal quality. And while it’s most visible on white, it affects all colours to some degree.
Our decals are made from a 5-layer, 1mm thick rubber — the most durable available — and are built to last. But even the best material can’t block certain chemical reactions caused by the tyre itself. Here’s what’s really going on.
What causes tyre browning or staining?
The main culprit is tyre blooming, a chemical reaction that happens when compounds within the tyre rise to the surface and oxidise. One of the key chemicals involved is 6PPD (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine) — an antiozonant added to all modern tyres to protect them from ozone damage and UV.
When a tyre is exposed to air, heat and sunlight — either on the road or even while parked — these chemicals migrate out of the rubber and oxidise, forming a brown residue on the sidewall. This is completely normal and doesn’t affect tyre performance, but it can discolour decals if they’re applied before the tyre has stabilised.
We’ve even tested this ourselves — we left a set of brand new tyres outside in a heatwave for three days, let the oils and residue rise out naturally, then applied our decals. A year later, we saw the same car at a show and the decals still looked clean. This shows that it’s not just about mileage — it’s about giving the tyre time to “sweat out” the reactive compounds before fitting.
How tyre blooming affects decals
If decals are applied during this active chemical phase, the compounds — especially 6PPD — can seep into the top layer of the decal, causing staining or uneven colouring. This is most noticeable on white decals, but it happens on coloured ones too.
Once this browning sets in, it’s difficult to remove without damaging the decal. Light buffing usually doesn’t help and can even make things worse. This isn’t a fault with the product — it’s a result of surface chemistry at the tyre level.
Why we recommend 1,000 miles first
Tyres tend to release the most surface-level compounds within the first 1,000 miles. That’s why we strongly recommend driving on new tyres for that distance — or letting them sit outside for several hot days — before applying your decals. By then, the tyre sidewall is less chemically active and far less likely to stain the decal.
We’ve seen decals last 2–3 years or more with no browning at all when applied to tyres that had already done mileage or had time to stabilise — even when fitted during summer or in warmer climates.
Why browning can reveal tyre patterns underneath
One thing some customers notice is faint outlines or shadows of the tyre’s raised or indented lettering showing through the decal when browning occurs.
This happens because the decal stretches slightly over the tyre’s surface. Raised areas like logos or text sit tighter against the decal, creating micro-pressure points. These areas can absorb or transfer chemical compounds at a different rate than flatter parts of the tyre. As a result, when browning happens, it can show a pattern of the moulded tyre text underneath — even though it wasn’t visible originally.
It’s another reason we recommend applying decals once the tyre surface has had time to settle.
What if browning happens?
If staining does show up, the best solution we’ve found is to touch it up with a Uni Paint Marker PX-30. It’s highly pigmented, sticks well to our material, and provides a clean, lasting finish. It won’t reverse the staining, but it does a great job of masking it and restoring a fresh look.