Read the board by functionCopper, solder mask, legend, dielectric and interconnections perform distinct functions. Visible color does not identify the full internal construction.Read the board by functionA conceptual board illustration; colors identify roles, not a material gradeJ1R1 R2 R3 R4REV ACopperTracks, pads and planesMaskPatterned protectionLegendReadable identificationDielectricSupport and insulationInterconnectSpecified layer connection³Ô¹Ïtv · Engineering explanation · Conceptual, not to scale