As the drop-on-demand (DOD) inkjet industry moves towards higher print frequencies to achieve higher productivity, the nozzle recovery rate and turnover time becomes increasingly important, in that attempting to jet from a nozzle that has not fully recovered results in meniscus instability and poor reliability [1] [2]. We have developed a new, simple, and rapid quantitative technique to measure the microsecond relaxation time of inks at a timescale relevant to DOD inkjet waveforms by exploiting the Piezo-Axial Vibrator (PAV) [3]. This microsecond relaxation has been found to be directly relevant to the maximum inkjet print frequency achievable. This has allowed for inks of any type to be screened, compared for batch variations and tailored for suitability for specific high-frequency jetting applications. The results show that this relatively inexpensive and compact equipment can detect changes in the microsecond relaxation with a high degree of sensitivity, with the effect of dynamic fluid properties beyond surface tension, viscosity or density able to be detected and quantified, allowing for new formulations to be developed with higher print frequencies in mind.