Gráfica Popular (referred to in English as vernacular sign painting) is a form of visual expression that embodies the cultural identity of urban and rural sectors in Latin America. Recognized as a non-academic yet deeply cultural practice, it is rapidly declining in cities like Guayaquil, displaced by policies promoting the homogenization of public space and the expansion of digital reproduction technologies. This study emerges as both an educational and cultural response to this issue, exploring feasible and sustainable ways to integrate Gráfica Popular as an open educational resource within public school settings in marginalized areas. Using a mixed-method approach, the research engaged three groups: local citizens and popular sign painters, secondary school teachers, and design students, applying opinion surveys and action-based strategies with the latter two groups. Through questionnaires, workshops, and contextualized creative practices, the study combined statistical and thematic analysis to explore perceptions, knowledge, and attitudinal changes. Results indicate a widespread recognition of Gráfica Popular as a carrier of cultural identity, alongside a shared concern about its devaluation and loss. Both teachers and students showed improved understanding, motivation, and willingness to apply this visual knowledge in pedagogical processes. The discussion highlights the urgent need for pedagogical mediation between vernacular graphic heritage and digital platforms as a pathway to revitalize this endangered practice. The study concludes that the critical and creative incorporation of Gráfica Popular into educational processes strengthens contextualized learning and critical thinking and contributes to preserving a visual cultural heritage threatened by generational and technological disconnection.