Gel polish is light-sensitive, which is why it hardens when exposed to LED light during curing. However, it can also begin to harden if exposed to sunlight or natural light for prolonged periods. If your gel polish is stored near a window or in proximity to a light source, the exposure may cause it to harden inside the bottle over time. To prevent this, we recommend storing your Pink Gellac bottles in a cool, dark place, away from direct light. Additionally, avoid placing the bottles too close to your LED lamp and refrain from applying gel polish in direct sunlight. This will help preserve the quality and longevity of your products.