Part of the dermis, the papillary layer is where fingerprints, palm prints and footprints form, states Penn Medicine. The skin consists of three main layers from the outside inward: the epidermis, dermis and hypodermis.
The dermis layer, often called "true skin", consists of two layers: the papillary and the reticular layers, according to Penn Medicine. The papillary layer is the first layer beneath the epidermis, or the outermost layer, and connects to the epidermis via papillae. Some papillae carry blood to the epidermis, while others function as sensory receptors called Meissner's corpuscles. Two rows of these papillae form unique prints. These aid is grasping objects and help keep the skin less prone to tearing.
The reticular layer is more dense than the papillary and consists of strong, elastic, intertwined collagen fibers. Deep-pressure sensitive receptors, sweat glands, lymph vessels, smooth muscle and follicles are all located in the reticular layer.