Answer: The reticular level is responsible for the dermal properties of skin that are evident as cleavage lines.
The microscopic study of the cleavage line has shown that in the regions where the cleavage lines are linearly arranged the collagen fibres were found to be arranged in uniform direction in a regular pattern which confirmed that the regions where the cleavage lines were branched the direction of these lines from the shallow reticular layer below the papillary layers and the inner reticular layer had collagen fibres arranged irregularly. The cleavage line morphology is considered to be influenced by the collagen fibres of the reticular layers in epidermis from the shallow layers just below papillary layers in which the sweat and sebaceous glands are present.