Will Acrylic Display Boxes Turn Yellow? The Facts You Need to Know

Short answer - no, your acrylic box frame from Harten Frameworks won't yellow.

One of the questions we get asked most often at Harten Frameworks is whether acrylic display boxes, sometimes called Perspex boxes or shadow boxes, will turn yellow over time. It's a fair concern. You've invested in a beautiful custom piece to protect and showcase a cherished 3D object, memorabilia, or artwork, and the last thing you want is for the clear acrylic to cloud or discolour years down the line, ruining the view.

We've been crafting museum-grade acrylic box frames for decades here in Cheshire, working with everything from delicate sculptures to sports jerseys and historical artefacts. In that time, we've seen how the right materials hold up beautifully, while cheaper alternatives can let people down. The good news is that high-quality acrylic, the kind we use, simply does not turn yellow in any noticeable way when properly made and cared for.

Why do some acrylics yellow while others stay crystal clear?

Not all acrylic is created equal, and that's where a lot of the confusion comes from. Acrylic, or polymethyl methacrylate (PMMA) as it's technically known, can degrade when exposed to ultraviolet light from the sun or certain artificial sources. Over many years, UV rays can break down the molecular structure in lower-grade acrylic, leading to a yellowish tint. This tends to happen more with extruded acrylic, which is cheaper to produce and often used in everyday items like signs or basic covers.

On the other hand, premium cast acrylic is formulated differently. It's more stable from the start and, when combined with UV-stabilising additives, resists degradation almost completely. Brands like Perspex, ACRYLITE, and Tru Vue Optium offer versions with proven track records, many backed by 30-year guarantees against yellowing. These materials maintain their high light transmission and clarity even after decades of exposure.

In framing and display work, we go further by using museum-grade or conservation-grade acrylic. This blocks up to 99% of harmful UV rays, not just protecting your item inside from fading but also safeguarding the acrylic itself from any colour shift.

The acrylic we use in our display boxes

At Harten, every acrylic box frame we build uses top-tier, UV-filtering acrylic designed for long-term preservation. It's the same standard you'd find in major galleries and museums. Our boxes provide an all-around clear view, with tough, scratch-resistant surfaces that stay transparent for generations.

We've framed pieces that have been on display for over 20 years without a hint of yellowing. The natural UV resistance of good acrylic starts at around 70%, but our specialist glazing options push that much higher, ensuring the material stays as clear as the day it was made. It's lighter than glass, shatterproof for safety, and perfect for larger or deeper boxes where weight matters.

What can cause yellowing, and how to avoid it

Even the best acrylic can face challenges if exposed to extreme conditions, though it's rare with the quality we specify. Direct, prolonged sunlight is the main culprit, along with high heat or certain cleaning chemicals that might react over time.

Here are some straightforward ways to keep your display box looking pristine:

Keep it out of constant direct sunlight where possible. A spot with indirect light or behind UV-filtering window film works wonders.

Dust it gently with a soft microfibre cloth and mild soapy water. Avoid ammonia-based cleaners or abrasives that could scratch the surface.

If your piece is particularly valuable, we can advise on additional protective coatings during the build.

For most homes and offices, though, these precautions are more than enough. Our customers often hang their acrylic boxes in bright spaces without issues, thanks to the built-in protection.

If you're still worried

We understand that some items are irreplaceable, so peace of mind matters. That's why we only use proven, museum-quality acrylic in our boxes, and we're happy to talk through the specifics for your project. Many clients send us their objects for a full consultation, where we handle everything from design to secure installation.

If yellowing is a big concern, glass glazing is always an option for certain frames, though it doesn't offer the same all-sided clarity or safety as acrylic for full boxes.

In short, with the premium materials we select at Harten Frameworks, your acrylic display box won't turn yellow. It's built to protect and present your piece beautifully for decades, just like the museum pieces we work on. If you have a project in mind, get in touch, we'd love to help bring it to life with total confidence.