Carbon nanowalls were synthesised by downstream deposition in an expanding radiofrequency argon plasma beam discharge injected with acetylene and hydrogen. The obtained layers have been investigated by Scanning and Transmission Electron Microscopy, Selected Area Electron Diffraction, and Raman Spectroscopy. We present the influence of the substrate type on the material characteristics and report on the possibility to obtain free standing carbon nanowall layers. Also, the importance of pressure values and argon carrier mass flow rate during the deposition process is discussed in relation to the quality of the nanostructured material.