The disclosure relates to pad printing of video targets on a specimen for tensile or similar testing by a video extensometer. The pad printer (10) may include various improvements such as pneumatic pistons to vary the pad spacing; pad supports (36, 38) which vary their spacing between ink pick-up and printing thereby allowing for a range of printing for a given cliche or printing plate (16); automatic proportional gauge length calculation; and a combination of a mechanical boss and a magnetic plate to secure the printing pad(40,42) to the pad carrier (36, 38).