Meaning ❉ Marcel Grateau, a name associated with the late 19th-century evolution of hair shaping, presented the heated waving iron. This invention, while not conceived for the natural undulations of textured hair, nonetheless marked a significant point in the systematization of hair styling. It introduced a replicable method for achieving consistent waves, laying foundational principles for what we now understand as routine consistency in hair care practices. For individuals with Black or mixed-heritage hair, Grateau’s innovation highlights a historical turning point in thermal manipulation, prompting a closer examination of how external forces alter natural curl and coil patterns. The adoption of the ‘marcel wave’ within various communities, including those of African descent, exemplifies the practical implementation of heat for specific aesthetic outcomes. This historical application underscores the continuous need for careful discernment when employing thermal tools, emphasizing the preservation of hair’s inherent resilience and vitality against structural alteration.