The droplet separation from a liquid jet was investigated experimental
ly. Details of the shape of the thin liquid neck joining the droplet t
o its parent body were studied in terms of the fluid viscosity and the
jet diameter. As the viscosity increased, the neck rapidly elongated
creating a long thread. Its final diameter before rupture was approxim
ately one micrometer and seems to be constant within wide range of par
ameters varied. One or multiple breakups of the micro-thread were obse
rved, which produced micro-satellites, i.e. droplets in a micrometer r
ange. The experimental results only partly confirmed the predictions o
f Eggers' (Phys. Rev. Lett. 71 (1993) 3458) similarity solution. The p
redicted shape of the pinch-off region well overlaps the long thread o
bserved for very viscous liquids. However, the final jet diameter, ret
raction velocity of the thread and presence of multiple breakups diffe
rentiate the experimental evidence from the model expectations.