The clear case is the best-selling type of case in the world. And the most common complaint about it is: it turned yellow after six months. The good news: for polycarbonate cases, yellowing is slowed down, and partly it's dirt that can be washed off. The bad news: soft TPU always yellows, it's just a matter of how fast.
Why cases turn yellow
Soft TPU contains plasticizers that react with UV radiation and heat. The reaction changes the polymer structure, and it absorbs blue light, making it appear yellow. In addition, sweat, grease, and dyes from jeans seep into the porous surface. You can't clean the first part, but you can clean the second.
What Spigen does differently
- Polycarbonate back. Ultra Hybrid and Crystal Hybrid have hard PC backs that don't yellow. Only the frame is soft.
- Blue resin. The TPU frame contains a pigment that compensates for the yellow tint and extends clarity.
- Anti-fingerprint surface. A smoother surface gets less dirty and is easier to clean.
How to clean the case
- Remove the case and shake out dust from the inside.
- Prepare lukewarm water with a drop of dish soap. Soak the case for 5 minutes.
- With a soft brush (toothbrush), clean the corners and cutouts where grease accumulates.
- Rinse, dry with a microfiber cloth, and let air dry for 30 minutes. Only put it on the phone when dry.
For yellowed TPU, a mixture of baking soda and water (a paste for 10 minutes) or isopropyl alcohol on a cloth helps. Do not use bleach or acetone, as TPU will become brittle and crack.
Prevention
Do not leave your phone on the dashboard or in direct sunlight by the window. Alternate cases: many customers have a clear case for everyday use and a colored Tough Armor for the mountains. And keep in mind that a clear case is a consumable item: replace it after one to two years, also for protection, as aging TPU dampens less effectively.