Interfaces that exhibit tunable stiffness properties can yield dynamic haptic feedback and shape deformation capabilities. In comparison to the particle jamming, layer jamming allows for constructing thin and lightweight form factors of an interface. This work proposes five layer structure designs and an approach which composites multiple materials to control the deformability of the interfaces. It also presents methods to embed different types of sensing and pneumatic actuation layers on the layer-jamming unit. Through three application prototypes it demonstrates the benefits of using layer jamming in interface design. Finally, this work provides a survey of materials that have proven successful for layer jamming.