One of the most common questions among resin artists is whether or not all resin yellows over time. Yellowing can affect the appearance of resin art, jewelry, and other projects, especially when clarity is essential to highlight embedded objects or maintain a glossy, glass-like finish. Understanding why yellowing happens, which resins are more resistant, and how to protect your work can help you make the right choices for long-lasting, crystal-clear pieces.
Here’s a comprehensive look at why resin yellows, which types are less prone to discoloration, and what you can do to preserve the clarity of your resin projects.
Why Does Resin Yellow Over Time?
Yellowing in resin is primarily caused by two factors: UV exposure and oxidation.
- UV Exposure: Ultraviolet light from natural sunlight and artificial lighting can break down the chemical structure of resin over time, causing it to discolor. Even resins labeled “UV-resistant” may eventually yellow when exposed to prolonged sunlight. And while you may put a resin piece in a drawer out of direction light, it can still yellow over time.
- Oxidation: Exposure to oxygen can also cause gradual yellowing in resin. This is a natural process that happens over time as the resin ages.
While yellowing is a natural outcome for most resins, certain types and protective measures can significantly slow down this process.
Are Some Types of Resin More Resistant to Yellowing?
Yes, some resins are designed to resist yellowing longer than others. Choosing a high-quality resin with UV inhibitors can make a difference in the clarity and longevity of your projects.
- Epoxy Resin: Epoxy resin is one of the most popular types for art and crafting, but it’s generally more prone to yellowing than other resins, especially if exposed to sunlight. However, there are UV-resistant epoxy resins available that include stabilizers to slow down the yellowing process.
- Polyester Resin: Polyester resin, often used in industrial applications, is durable but tends to yellow faster than epoxy and polyurethane resins. It’s best suited for projects where slight discoloration is less of an issue.
- Polyurethane Resin: Polyurethane resin is highly UV-resistant and often used in outdoor applications. It’s generally more expensive but offers better clarity retention and is less prone to yellowing.
- UV-Resistant Resin: Some epoxy and polyurethane resins are specifically formulated with added UV stabilizers. Look for products labeled “UV-resistant” or “non-yellowing” if maintaining clarity is crucial for your project.
Choosing a UV-resistant resin can greatly improve the lifespan and appearance of your artwork, especially if it will be exposed to light.
How to Slow Down Yellowing in Resin
While some yellowing over time is inevitable, there are several ways to protect your resin art and slow down the process.
1. Store Finished Pieces Away from Direct Sunlight
Sunlight is one of the biggest factors in resin yellowing, so it’s essential to store finished resin pieces in a location that minimizes exposure to UV light.
- Tip: Display your artwork in shaded areas or under UV-filtered glass to prevent direct sunlight from affecting the piece.
- Pro Tip: For resin jewelry, consider keeping pieces in storage bags or boxes when not in use.
2. Use UV-Resistant Resin
As mentioned, UV-resistant resins are designed to minimize yellowing. Look for products that explicitly state UV resistance or “non-yellowing” to get the best protection.
- Tip: Higher-quality, UV-resistant resins are often more expensive but offer greater protection against discoloration.
- Pro Tip: Research reviews and brand specifications to find resins with proven resistance to yellowing.
3. Apply a UV-Protective Topcoat
A clear UV-protective topcoat or varnish can add an extra layer of protection to your resin piece, especially for items exposed to sunlight.
- Tip: Look for UV-protective sprays or coatings in the art or hardware sections of craft stores. Ensure they’re compatible with resin.
- Pro Tip: Apply multiple light coats, allowing each one to cure thoroughly, for optimal protection.
4. Avoid Using Heat on the Resin Surface After Curing
Heat exposure can accelerate the yellowing process, so it’s best to avoid placing resin pieces near heat sources after curing.
- Tip: Avoid direct sunlight or high-temperature environments like car dashboards, where both heat and UV exposure can speed up discoloration.
- Pro Tip: If using a heat gun during curing, apply only briefly to minimize the risk of yellowing.
5. Store Resin Properly Before Use
Even before curing, exposure to light and heat can affect resin. Store your resin in a cool, dark place to help maintain its clarity before and after it’s applied.
- Tip: Keep resin bottles tightly sealed and stored in a dry, dark place, such as a cabinet or box, when not in use.
What to Expect Over Time
Despite the best care and UV-resistant materials, all resins will likely experience some degree of yellowing over time due to natural aging. However, with proper selection and maintenance, you can significantly slow this process and enjoy long-lasting, clear resin art.
Final Thoughts
While yellowing is a common concern, choosing a high-quality, UV-resistant resin and taking preventive measures can preserve the clarity of your work for years. By selecting the right materials, minimizing UV exposure, and applying protective topcoats, you can create resin art and keepsakes that maintain their beauty and remain crystal-clear longer.
Understanding and planning for the natural aging process of resin allows you to create pieces that stand the test of time, preserving the vibrancy and clarity of your artwork.