Removal of graffiti from porous masonry structures poses significant conservation challenges particularly with spray paint, due to adhesion properties and penetration within the pores. Historic brick, generally softer and with a higher porosity compared to dense stone or modern brick, is particularly vulnerable to paint absorption and susceptible to surface alteration as part of the removal process. Micro-abrasive cleaning, which employs fine abrasive particles at low pressures to wear away the paint, offers a controlled alternative to other methods, reducing direct exposure to harsh chemicals, discoloration, and excessive material loss. However, its effects on historic brick remain underexplored.

This study assesses cleaning effectiveness and material impact through color and surface texture analyses before and after cleaning tests. Fire-skin retention serves as an additional key indicator of the aggressiveness of this method, beyond changes in surface roughness. By combining instrumental analysis with visual and tactile assessments, this research aims to inform graffiti removal strategies for historic brick and support broader conservation cleaning practices for sensitive surfaces.