Every output device may have a certain discrepancy between the desired result and the actual result. This discrepancy is caused by dot gain. To compensate for this discrepancy, you need to calibrate your output device.

In practice, this happens in the Curve Editor, where Apogee calculates a dot gain compensation curve so that your output device produces the desired results. The resulting curve may be irregular to produce the desired dot gain.

Depending on the type of output device, you may have to calibrate it regularly. The print results may differ for instance because of climatic changes.

In Apogee, Calibration is only used for the press. For imagesetters and platesetters, Apogee uses Linearization.

Linearization is a special case of calibration. It is especially used for imagesetters and platesetters. Through linearization, you can adjust the Stimuli values so that they equal the Wanted values during output. In other words, you linearize the Stimuli values with the Wanted values, unlike Calibration, where the curve is not necessarily linear.

Before Apogee can linearize your output device, you need to print a test page. The test page is based on the Stimuli values. These are the measuring points that will be used to calculate the linearization curve. They will appear on the test page as printing blocks. If you measure the printing blocks with a densitometer, you obtain the Measured values. The Wanted values are the desired results. The difference between the Measured values and the Wanted values is the dot gain of your output device. In the Curve Editor, you need to fill in those values in the Values table or import them from an existing file.

Simulation can be considered as Calibration for special needs. This means that you are free to use Simulation curves anyway you want. You can for instance purposely use a nonlinear curve to obtain a certain dot gain or other special effects.

This is why there are no Measured values for Simulation. The curve is solely based on Wanted values, which is the desired curve.

This simulation technique is very common in packaging, where flexography is used.