A detailed study on the influence of the substrate loading (relative to the catalyst content) and supply pressure of the feedstock on the diameter and distribution of the number of walls in carbon nanotubes in alcohol chemical vapor deposition (CVD) is presented. Here we show how one can modify the technique for the bulk formation of high quality desired nanotube types: single-walled, double-walled or multi-walled CNTs. The influence of the concentration of the catalysts with respect to the substrate concentration was examined to select the optimal conditions in terms of the sample quality. Resonance Raman spectroscopy and high resolution transmission electron microscopy have been applied to characterize the samples.