This study proposes BlowFab, a prototyping method used to create a 2.5-dimensional prototype in a short time by combining laser cutting and blow molding techniques. The user creates adhesive areas and inflatable areas by engraving and cutting multilayered plastic sheets using a laser cutter. These adhesive areas are fused automatically by overlapping two crafted sheets and softening them with a heater. The user can then create hard prototypes by injecting air into the sheets. Objects can be bent in any direction by cutting incisions or engraving a resistant resin. The user can create uneven textures by engraving a pattern with a heat-resistant film. These techniques can be used for prototyping various strong inflatable objects. The finished prototype is strong and can be collapsed readily for storage when not required. In this study, the design process is described using the proposed method. The study also evaluates possible bending mechanisms and texture expression methods along with various usage scenarios and discusses the resolution, strength, and reusability of the prototype developed.