The formation of directly fused porphyrin tapes attracted the interest of the scientific community because of their electronic and optical properties such as extremely low bandgap, NIR and two photon absorption. The synthesis of these compounds is tedious because of their low solubility and require the introduction of solubilizing substituents adding further synthetic efforts.^[1] Moreover, these materials are hard to process and integrate into device while the solubilizing substituents hinder the π­-π interactions affecting the properties of the resulting materials.^[1],[2] These drawbacks were circumvented with the oxidative Chemical Vapour Deposition (oCVD) of phenyl meso-substituted porphyrins, which allowed to achieve in a single step the synthesis, deposition and doping of polymeric fused porphyrins tapes thin films from commercially available chemicals.^[2] Our approach allows the deposition of patterned films and is compatible with sensitive substrates such as paper or polymers (Figure 1a). Using Ni(II) 5,15–(diphenyl) porphyrin (NiDPP), 5,10,15–(triphenyl) porphyrin (NiP₃P) and 5,10,15,20–(tetraphenyl) porphyrin (NiTPP), we elucidate the reaction active sites, the side reactions (Figure 1b) and the differences to solution based approaches via high resolution mass spectrometry, UV-Vis-NIR spectroscopy, electron paramagnetic resonance (EPR) and Density Functional Theory (DFT). We also investigate the effect of the central metal ion on the direct fusion reaction of Fe(III)Cl, Co(II), Ni(II), Cu(II), Pd(II), H₂ and Zn(II), 5,15–(diphenyl) porphyrins in oCVD. Furthermore, the electrical, electronic and morphological properties of the prepared thin films were thoroughly investigated by means of X-ray Photoelectron Spectroscopy (XPS), Helium Ion Microscopy (HIM) and Conductive Atomic Force Microscopy (C-AFM). [1] T. Tanaka, A. Osuka – Conjugated porphyrin arrays: synthesis, properties and applications for functional materials – Chem Soc Rev. 2015, 44, 943. [2] G. Bengasi, K. Baba, G. Frache, P. Gratia, K. Heinze, N. D. Boscher – Conductive Fused Porphyrin Tapes on Sensitive Substrates by a Chemical Vapor Deposition Approach – Angew. Chem. Int. Ed. 2018, DOI: 10.1002/anie.201814034. Figure 1) a) The chemical vapour deposition reaction of NiDPP and FeCl₃ yields a homogeneous and conductive coating also on sensitive and bendable substrates which evidences the suitability for modern optoelectronic devices. b) Reaction schemes for the CVD reaction of NiDPP and FeCl₃ and side reactions observed during the deposition (chlorination, cyclization of the phenyl ring). Figure 1