Colour profiles and ink density for predictable output

The proof you approve and the print that comes off the flatbed should be the same picture. They are only the same when the whole pipeline speaks one colour language: the file, the RIP profile, and the ink density all answering to the same rules.

The profile is the translation layer

A colour profile tells the machine how much of each ink to put down for a given colour on a given material. Change the substrate or the ink and the same RGB value prints differently. That is why a studio fixes one profile per machine and ink set, and why switching profiles mid-job is the fastest way to lose a client's colour.

Ink density — how much is too much

Density is how saturated the ink lays down. Too little and colours look washed; too much and ink pools, takes forever to cure, and muddy dark areas blend into each other. The target is set on the machine and kept steady, so shadow detail survives and fine type stays sharp.

Making it repeatable

The skill is boring on purpose: fix the profile, fix the density, and measure the same patch chart at the start of every shift. When the numbers repeat, the colour repeats, and the client gets the same blue they signed off a year ago.