Al2O3, but it will also increase the amount of overreacted material (light blue circle in Figure ). This is relatively regardless of tuning the remaining processing parameters (top left radar plot in Figure ). In order to avoid overreaction, an alternative route is to slightly increase the water fraction in the precursor while initially keeping the magnetron power (x3) and the Al(NO3)3 concentration fixed (orange circle and bottom right radar plot in Figure ). Subsequently increasing the latter two parameters leads to increasing yield of δ-Al2O3, but this time at lower overreacted phase. Very obviously, the overall degrees of freedom decrease in this process: the product resilience to variations in processing conditions decreases for higher levels of optimization. variations in that input parameter.