Described herein is a method for monitoring the deformation of a surface (100) of a band (200), comprising: applying an elastic material layer (10) on said surface (100), covering it at least partially, wherein said elastic material layer (10) has a substantially rectangular shape and is engaged on said surface (100) at two opposite ends (11, 12); wherein said elastic material layer (10) has an active zone (20) comprising a plurality of through apertures (21); each aperture (21) having a substantially elongated shape, wherein each aperture (21) is adapted to deform, as a function of the elastic or plastic deformation of said surface (100), between: a first configuration, substantially closed, wherein said plurality of through apertures (21) block the view of said covered surface (100); and a second configuration, substantially open, wherein said plurality of through apertures (21) allow viewing, at least partly, said covered surface (100). A band and a sensor are also disclosed.