Owing to its extraordinary nanolamellar microstructure, chemical vapor deposited Ti _1-xAl _xN has gained considerable interest in the recent years. However, the formation mechanism of the nanolamellae is not yet understood and is currently subject of intense research. In this publication we have deposited Ti _1-xAl _xN coatings at varying temperature, pressure and rotation speed of the central gas feed. Transmission electron microscopy has been conducted in order to quantify the lamella periodicity and correlate it with the deposition parameters. This work demonstrates that nanolamellae can be obtained over a wide range of deposition parameters and, more importantly, that the periodicity does not seem to depend on the gas feed rotation but can be correlated with deposition temperature and pressure.