Cutin's main role is to prevent the the plant leaf from water loss, cutin is thick in shape , but I need to know where is the location of it ,for example is it in the lower epidermis or in the upper epidermis ?
Cutin is a waxy substance comprised of a mixture of two or more oliphatic acids. It is secreted onto the whole above-ground surface of the plant: leaves, stem, flower-buds. As such, it covers the whole of the outside of the plant - excepting the stomatic openings which serve to enable wanted moisture loss.
It's secreted by the epidermal layers of the tissues and has served to enable the plants to evolve beyond the marine environment in which they originated in excess of 450 million years ago. It provides a hydrophobic coating, preventing unwanted moisture-loss from the plant.
Cuticle is the name given to the coating of the leaves, cutin to the chemical mixture it comprises.