Method of using a shape-formable apparatus. A shape-formable apparatus can include an envelope defining a chamber, a port positioned to fluidly couple the chamber with ambience, and at least two locking sheets positioned in the chamber in an at least partially overlapping configuration. Each locking sheet can include a major surface, and at least a portion of each locking sheet can be patterned to include solid regions and open regions, the solid regions being movable with respect to one another within the major surface. The method can include providing the shape-formable apparatus in a first state forming the apparatus into a desired shape and reducing the pressure in the chamber to change the apparatus from the first state to a second state in which the apparatus is substantially less formable than in the first state.
