ᐅ Why do BILLY shelves change color over time?

Hello everyone,

I have a question that has been on my mind for a while: Why do IKEA Billy shelves change color over time? I’m not referring to dirt or physical damage, but rather an actual change in the color tone or intensity on the surface of the shelves themselves.

I’ve noticed that the originally very even, often somewhat matte white on my Billy shelf, which I have used over the past few years, gradually becomes a bit yellowed, especially along the edges or areas exposed to more sunlight.

I suspect this effect is related to the type of coating and exposure to light or environmental factors, but I can’t find any solid information about how or why exactly this happens, or how much it varies depending on the surroundings.

Can someone explain from a technical perspective why Billy shelves change color? Or perhaps share tips on how to minimize discoloration?

Thanks in advance for any well-informed answers!

Discoloration is mainly caused by UV radiation affecting the surface.

Plastics and coatings on the BILLY shelves often contain white pigments that yellow over time due to UV exposure.

Additionally, the MDF material itself reacts to moisture and light, which influences color tones.

Hello man-la, your powers of observation are really impressive! 🙂

You can almost compare BILLY shelves to human hair—the more sunlight they get, the more the color fades or changes. Especially due to UV radiation, the material basically "ages," and the white tends to shift toward a warmer tone, just as you described.

Additionally, everyday tiny micro-scratches occur, which refract light differently—altogether, this results in a gentle yellowing effect.

If you want to avoid this, I would recommend not placing the shelf directly next to a large window and wiping it regularly with a dry cloth—moisture and dirt can intensify this effect. 😉

To better understand the color changes in the BILLY shelves, we should first look at the material composition. The BILLY shelf is made of MDF panels laminated with paper coated in melamine resin. This means the surface is not painted but covered with a thin layer of plastic that forms the white finish.

JORGERON schrieb:
The discoloration is mainly caused by UV radiation affecting the surface.

Exactly, the melamine coating contains white pigments, often titanium dioxide, which initially provide excellent coverage and brightness but are chemically attacked by UV radiation over time. This reaction can cause slight polymer breakdown, resulting in yellowing.

Furthermore, it is important to know that the MDF material inside also reacts slightly to changes in humidity and temperature fluctuations.

This combination of chemical aging of the coating and mechanical environmental effects explains the varying color reflections on angled edges or areas exposed to sunlight.

Therefore, it is worth considering if your shelf is placed directly behind a south-facing window, where UV exposure is highest.

Question: How long has your shelf been in its current position, and what is the indoor climate like (humid/dry)? This can be crucial!

bapar schrieb:
Question: How long has your shelf been in its current position, and what is the indoor climate like (humid/dry)?

Thank you for the detailed explanation and the follow-up question! My shelf has been in almost the same spot in my living room for about seven years. The room is usually quite dry – I would estimate the humidity level to be around 40 to 50%.

The window area right next to it is quite large, and especially in spring and summer, a lot of sunlight comes in, as it faces south. So it’s quite possible that UV light has the strongest impact.

TARAON schrieb:
If you want to avoid that, I would recommend not placing the shelf directly next to a large window

That’s a bit difficult because my room doesn’t offer many alternative arrangement options. Therefore, it would be really interesting to know if there are care products or special coatings that can at least improve UV resistance, for example as a temporary solution.

Hello man-la and everyone else,

I would like to add a brief overview regarding maintenance and possible protective measures, as this topic is often misunderstood.

1. Material & Aging: As mentioned earlier, the melamine coating is sensitive to UV light. This means that exposure to sunlight causes molecular changes that make the white surface appear yellowish.

2. Cleaning Products: Usually, a damp, soft cloth is sufficient to remove dust from BILLY shelves. Strong cleaners or solvents should be avoided, as they can further damage the surface.

3. Protective Coating: For additional UV protection, there are special plastic sealants that can be applied carefully. It is important that these are suitable for melamine and do not trap moisture, as this could cause the MDF to swell.

4. Positioning: If relocating the shelf is not an option, using UV-protective window films or curtains that allow filtered light during the day may help.

5. Regular Maintenance: A combination of dusting, avoiding direct sunlight, and gentle cleaning significantly extends the lifespan of the surface.

In summary: Fully preventing color changes in this material is difficult, but the timeframe can be significantly extended.

If there is interest, I can also provide tips on specific products or application steps.