"Liquid White" is a type of oil paint medium that is used in the wet-on-wet painting technique, which is a technique that Bob Ross was famous for. It is one of three Bob Ross Liquid Basecoats that are essential to the Bob Ross Wet-on-Wet Technique® . The function of liquid white in Bob Ross painting is to create a smooth and wet surface on the canvas, which makes it easier to blend colors and create the desired effects. It is a blend of materials that allows oil paint to flow more smoothly and helps to increase the drying time of the painting. It is important to note that liquid white is not the same as white gesso, which is used for priming the canvas and is not used in the wet-on-wet painting technique.