Rollers are used to guide the web material along a predetermined path through a process
line. Let's take a printing press as an example. The path will vary on most presses as different
print jobs have varying print requirements (number of colors, cold seal, side of printing,
drying time, etc.). The web path will also vary depending on the drying times and drying
temperatures of the inks. Under the inspection head, rollers are used to present the web to
the cameras in as stable a condition as possible. There are a couple of configurations often
used for both surface inspection and print inspection.