Special storage precautions are necessary to prevent LightScribe discs from fading. HP's LightScribe website warns users to "keep discs away from extreme heat, humidity and direct sunlight", "store them in a cool, dark place", "use polypropylene disc sleeves rather than PVC sleeves", and also notes that "residual chemicals on your fingers could cause discoloration of the label image". Such chemicals include common hand lotions and hair care products. Users not observing these precautions have reported LightScribe discs to become visibly faded within two months in the worst case. This drawback makes the technology unsuitable for applications involving continuous handling, and for such popular uses as car music compilation discs, which typically have unavoidable high light and temperature exposure. Since many disc players present internal temperatures significantly higher than room temperature, LightScribe discs should also not be left in disc players for long periods of time.