Clear plastic cups are most commonly made from PET plastic. PET, or polyethylene terephthalate, is a clear, strong plastic that is widely used for food packaging and household containers. It is safe for use with food and beverage products, and it can be easily recycled. Clear plastic cups made from PET plastic are typically clear and transparent, with a smooth surface that makes them easy to clean. They are also relatively lightweight and shatter-resistant, making them ideal for use in a variety of settings.