The first International Electrotechnical Commission (IEC) standards for vision-based measurements of inkjet droplet speed and volume from inkjet print-heads were recently prepared for publication by the Technical Committee working group WG3 for Printed Electronics equipment. These IEC/ISO standards could be more widely adopted for other inkjet printing applications and establishing the relative performance of drop-on-demand (DoD) inkjet print-heads and inks. The underlying behavior of inkjet drops and effects influencing these standards for in-flight drop measurement methods are discussed.