Gradation curves

Where do I get gradation curves from?

• From the software used to calibrate / standardize the printing press.
• From measurements of the sample print.
• Use the default Offset gradation curves listed in the GMG OpenColor Database. These curves are ISO curves which conform to the PSO (Process Standard Offset). For Flexo printing, it is recommended to create your own gradation curves.
• Create one yourself. Since the values between the fulcrums are interpolated in a linear way, it is important to define a curve with more than just two or three fulcrums.

How do I create a gradation curve?
You can create a gradation curve either by selecting and duplicating an existing curve or by creating a gradation from scratch, as described in the following.

1. On the Database tab, click New Gradation.
   A new gradation curve is displayed as a straight line.
2. Enter a name for the gradation.
3. Select the Type. In case of a Tone Value Curve, select the Calculation Method.
4. Left-click on any point of the curve to add fulcrums. (Remove fulcrums by right-clicking on a fulcrum.)
5. Click-and-drag fulcrums, or enter values into the gradation table to shape the curve.
6. Save the gradation to the Database.

Values in-between fulcrums are interpolated by linear regression. We recommend to add fulcrums in 10% or even smaller steps.