When subjected to continuous visible laser irradiation, the dried thin film underwent a significant alteration in both color and surface topography. Specifically, the film changed from brown to black, and its previously smooth and flat surface became visibly rough and porous. This transformation is evident in high-resolution scanning electron microscopy (HRSEM) imaging of the composite presented in Figure , which reveals the transformation of the relatively smooth surface to an immensely macroporous structure as a result of the lasing process. The thickness of the a single-layer film composite cross-section was analysed using a lamella extracted from the anode with a focused ion-beam (FIB), where a thickness of approximately 5 microns can be observed in Figure . Porosity measurements depicted in supplementary figure based on HRSEM imaging in Figure show an average pore diameter of approximately 7 microns and an overall porosity of 49%. Additional higher magnification HRSEM imaging is depicted in Figures and, before and after laser writing, respectively, providing a more detailed depiction of the substantial changes in surface topography and porosity, and the inner workings of the highly macroporous architecture.