Why Does Resin Turn Yellow Over Time? (Guide & Tips)

Discolouration is a common concern for anyone working with resin, especially if you value a crystal-clear or vibrantly coloured finish. Understanding why resin turns yellow over time helps you make better choices for long-lasting results.

The Main Cause: UV Exposure

Ultraviolet (UV) light is the leading culprit behind resin yellowing. Both sunlight and artificial light can trigger a slow chemical change in most epoxy formulas, resulting in a gradual amber or yellowish tint as the years pass. Even indoor installations are not immune, especially if exposed to daylight for prolonged periods.

How to Minimise Yellowing

The best defence is to choose a resin that includes robust UV filters or stabilisers. For example, Art Pro Deluxe has powerful UV protection designed specifically to slow yellowing in artistic and surface coating applications. For projects that require thicker pours, selecting a deep pour formula—like those used for tabletops or castings—can offer additional longevity. Applying the resin in suitable thickness and avoiding unnecessary exposure during curing can also help retain clarity.

Practical Tips for Lasting Clarity

Store finished pieces away from direct sunlight.
Opt for resins formulated with UV resistance, such as “Art Pro” and “EpoxyTable 5-Five” for larger projects.
Always follow the manufacturer’s recommendations for mix ratios and curing to achieve the most stable results.

When This Matters Most

Maintaining clarity is especially important for art pieces, jewellery, tabletops, and surfaces where a clean, bright appearance is the goal. If you are creating decorative objects intended for prominent display, yellowing resistance should be a top priority.

Related guides

Learning what causes resin to yellow and choosing UV-resistant products ensures your pieces stay brilliant for years. For more insight into resin behaviour and how to safeguard your projects, see our main guide on what causes resin.