A White Layer
This renders every object that is contained in that layer to the target plate (usually White). So whatever the color is of the object it will be rendered with overprinting white. The white layer output method can be changed anytime during the process.
Multiple layers with different specifications are allowed. The order of the layers influences the rendering and thus also the white. For example a documents first layer maybe be ‘Flood’, followed by a normal layer rendering the color objects and then again a white layer with ‘Density’ for a subset of the objects that are present in the normal layer. ‘Spread’ and ‘Choke’ can be created as required.
The process is applied at the RIP stage on ‘the fly’, matching the pixels and output resolution.
This system enables a mix of different white generation, referencing any part of the document and a visual editor to edit the white effects.
White Layers are an addition and do not replace tools like:
- Plate remapping
- Drawing and editing White objects
They can be used in combination with each other.
Please be aware the following situations will lead to unexpected results:
Removing the White plate: If the plate that is specified in the White Layer is missing then the content of the layer will be rendered using the original color.
Cutting tools: Changing the White Layer to a cut will link to the tool of the cutter. The output will be rendered as if the layer is a normal layer. If changed back to Printer the white generation will again be active.
Supported White Methods
A full coverage, irrespective of the image content.
Everywhere there is color white is generated.
For every pixel where the luminosity is not ‘1’ (0=Black, 1=White) white is generated.
Objects that result in a white color will generate white.
For every pixel where the luminosity is ‘0’ white is generated (for example CMYK(0,0,0,0) or RGB(255,255,255). Where no object is placed there is no white.
The Alpha channel is copied to the white channel for every pixel.
No white will be generated for areas where no objects are placed (see also Under White).
For every pixel the inverse of the luminosity value is copied to the white channel.
Light objects generate little white and dark objects generate much white. Effectively the objects are rendered to a grayscale image, this image is inverted and used as white.
The inverse of Density and thus generating much white where light objects are and little white where dark objects are. No white will be generated on places where no objects are.
Described as a percentage, enables control of the quantity of the color.
This controls the edge of the color to follow the edge with an offset. Described in mm, it enables a small or large adjustment to aid a devices registration shortcomings.
White can be previewed using a specific color so it is visible against the document background and can be adjusted to contrast with specific artwork colors.
Examples / FAQ
White under Color
If you wish to print white onto a black media for example.
How to do this:-
Open the file in Editor.
- Check you have the right machine and media set, it will need to be a white ink device and PMM setup.
- Pick the colored object you wish to have the white under
- Open the White generation tool.
- Select White under color
- You may want to add some choke or spread (allows the white edge to finish just inside or outside the selected colored object, defined in mm).
- This is visible once applied in the preview of the Editor. Choke is set to 0.1mm.
White under White
Perhaps you have an artwork with a white element that needs to be printed white if you have a coloured substrate. This enables you to pick all objects automatically that are white in colour and define it all to have the white ink applied there.
This can be checked by switching off the other channels in the output tab to leave the white only visible. The white is then displayed as black.
This is ideal for ‘reversing out’ an image, printing white ink onto black media.
Using a ‘greyscale’ image.
- Select ‘Generate White’
- Click ‘-Density’. This will put white ink emulating the lightness of the greyscale image, so where there is no colour white will be 100%, if there is 25% black then 75% of white will be applied.
- A ‘White -Density’ layer has now been created, so the original layer needs to be deleted, to leave the white channel as the only printing element.
To see the White channel clearly, turn off the other colors in the Output Channels panel.
- Use the tonal curve to remove about 28% at the bottom of the white ink channel, this lets the black areas become ‘cleaner’ and white shows in the highlights, reducing the ‘spray’ of white ink in darker parts of the image.
This is now complete a can be printed to produce the white on black image.