The trend in modern interior design leans towards curved and shaped surfaces. This cannot be achieved with flat materials without additional effort. Materials from renewable resources, such as wood-based materials, are material- and energy-intensively processed to enable larger deformations. Therefore, this study deals with methods to increase the deformation potential of adhesive-free, high-density fiberboards. One method is plasticizing in a saturated steam atmosphere, which is well known from the bending of solid wood. The second is the application of a special kerf pattern that geometrically increases the deformability. The combination of both methods was also investigated. Uniaxial tensile tests were performed to evaluate the deformation potential of the methods used. The strain along and transverse to the tensile direction, as well as the modulus of elasticity and Poisson’s ratio, were determined as results. All the methods investigated lead to an increase in the maximum strain along the tensile load: steaming by a factor of 2, kerf patterning by a factor of 4, and the combination by a factor of 10 as compared to solid fiberboard. The application of the kerf pattern causes an auxetic material behavior with a negative Poisson’s ratio. The combination of both methods reduces the modulus of elasticity by a factor of more than 100. Overall, the investigated methods are suitable for increasing the deformation potential of fiberboards with regard to the forming of 3D-shaped surfaces.