The most common type of bathtub doors is the sliding door. These doors are typically made from tempered glass and can be installed either as a stand-alone unit or as part of a larger shower enclosure. Sliding doors are easy to use, as they simply slide open and closed along a track. They also provide a sleek, modern look to any bathroom. Another popular type of bathtub door is the hinged door. These doors are usually made from wood or metal and swing open like a regular door. They are great for providing an extra layer of privacy, since they can be closed completely when not in use. Finally, folding bathtub doors are becoming increasingly popular. These doors fold up like an accordion and can be tucked away when not in use, allowing for more space in the bathroom.