Hand paintings are commonly depicted in rock art around the world from a wide variety of historic periods and cultures. According to Wiki "The most common rock art element found around the world, the human hand, exemplifies several pictography types. A technique used since the Neolithic is spraying around a hand, resulting in a negative image. The more common positive print was often made with pigment applied to the hand and transferred to the rock." See also http://www.bradshawfoundation.com/hands/