痂皮[kahi] crust

乳痂[nyuuka] cradle cap

バナナの皮[banananokawa] banana peel
一皮[hitokawa] unmasking
化の皮[bakenokawa] masking one's true character
化けの皮をはぐ[bakenokawawohagu] to unmask (someone's true nature)
果皮[kahi] pericarp (ripened ovary wall forming part of a fruit)

外皮[gaihi] investment (in the sense of outer layer)
角皮[kakuhi] cuticle
桜皮[kanba] birch (esp. Japanese white birch)
乾皮[kanpi] dried hides
雁皮紙[ganpishi] traditional Japanese paper made from the fibre of plant species Diplomorpha sikokiana (high quality, glossy)