This publication compiles a large collection of scale-models made during more than 25 years of work in the architect Alberto Kalach's workshop. The elaboration of models in the design process is a habit almost forgotten. Education in architecture is highly dependent on technology and increasingly distant from the study of space through manual processes. It is not a nostalgic and conservative idea - for who writes this was formed under those conditions - nor to suggest that current procedures, which are also fundamental in practice, must be supplanted. However, the use of models gradually moves away from the processes and falls into other uses -ornamental or commercial, for example- always aspiring to some artificial cleanliness and perfection. Starting from this idea, if these objects are increasingly foreign to the processes, it is even more complicated to explain the entire experience of an architect or a workshop only through their models. However, with this premise the exhibition and the accompanying catalog were made. Beyond tracing a trajectory, the book exposes the multiple vertices that make up his work: the right paths, the redirected ones, the wrong ones. Paths or strategies that fluctuate between the logical solution and utopia, narrated through more than 160 models, classified by their typological, structural, morphological and material characteristics. Urban scale projects are explored, such as the proposed air terminal for Texcoco; towers, such as Reforma 27 or Constituyentes 41; studies of roofs of different shapes, sizes and materials; some prototypical projects -collective housing- and others that are resolved from a single container space -such as the Vasconcelos Library or the Total Theater. They are exhibited as a repertoire of all the variables found around similar solutions, always betting on the whole and not on the exception. Likewise, through texts by Juan Palomar, Pablo Goldin, Mario Ballesteros and Juan Carlos Cano, the meaning of the model in its objectual quality and outside it is analyzed. According to the authors, the model can be a tool, a source of inspiration or dialogue and an indispensable link between the culmination of the project and its execution. Even where the project can not be executed in reality, the model serves as a compensation for what could not exist and the tangible evidence of an idea. This inventory, beyond the almost obligatory meaning that refers to an extensive record, is a collection of the shared experiences of the workshop, which allows both the identification of who already knows the work and the learning of who just discovered it. Regardless of whether they are crude or delicate forms, realizable or absolutely utopian, the importance of their models lies not in their perfection, but in the ideas they represent. They are important weapons in the vindication of manual work in the construction of the knowledge of the space and an incentive to the imagination. "There are scale-models on paper, in corrugated cardboard, in balsa and solid wood, in bronze, in foam ..." (HKB Translation) --Page 11.