Functional atomic force microscopy (AFM) techniques are proposed as a high resolution tool to understand relevant physical properties of colorants and printing substrates at nanoscale. In this work, we present an exploratory AFM study of colorants used by three digital printing technologies: LaserJet, Indigo, inkjet and two printing substrates: white paper and transparent media. Surface morphology and phase-contrast imaging are performed using amplitude-modulation (AM) AFM and measurements of surface potential and capacitance gradient are measured through 2^nd harmonic Kelvin Probe Force microscopy (KPFM). Compositional mapping contrast is analyzed using both techniques. Non-homogeneous mechanical properties are clearly evident in the AM-AFM images while the variations of local electrical properties are apparent from the KPFM studies.