Generally, the default values will provide you with good results, but you can also define (more precise) custom settings. The Noise settings are automatically applied according to the associated Media and Printing Process.

When simulating Flexo printing, the proofs might appear "too smooth" if compared to the original print. With the Noise option (Printing Process > Use Noise), you can add artificial "errors" with a customizable frequency and intensity to the proof so that print and proof match as closely as possible.

Experience has shown that a frequency of 30 and an intensity of 3 are rather maximum values. In most cases, the required frequency lies within 15–20, the intensity amounting to no more than 2.

The option Missing Dots simulates non-printing raster dots often occurring in gravure printing. This typical characteristic in gravure printing is caused by a non-ideal ink transfer from the gravure cells onto the printing medium due to a non-ideal take up of the ink by the paper and/or due to cell clogging. The amount of missing dots depends on the type of printing machine and medium used. Missing dots are more pronounced when an uneven or low-quality medium is used, for example, for specific applications in the packaging industry.

How does it work?

Missing Dots works similar to a filter that adds noise to the image. Please note that missing dots are therefore less pronounced if noise simulation is used in the same profile.

Define the amount of missing dots (range: 0–10) according to the characteristics of the printing machine and media used for the gravure printing process. The lower the screen frequency, the lower is usually the amount of missing dots you need to obtain the same visual appearance. Generally, an amount less than 1 is already sufficient for a realistic missing dots simulation.

If different color channels have different values for the Amount of Missing Dots, some of the missing dots will be colored.
Example: the Amount of Missing Dots is Cyan = 0.25, Magenta = 0.5, Yellow = 0.5, and Black = 0.5 because the ink transfer is better for the Cyan channel than for the other channels (and the Colored Dots level is set to 0). In a gray area of an image, where the ink is equally distributed for all color channels, half of the resulting missing dots will have a Cyan color. In a pure Cyan area of the image, the number of missing dots will be half the number as in other areas.

The size of the missing dots can be defined according to the screen frequency used in the plate-making process. You can also adjust the size of missing dots according to the visual appearance of the proof by adjusting the Screen Ruling parameter.