White Ink Settings

 

White Ink Control Tab

white_ink_control_tab.pngBy far one of the most important control sets, particularly in a white-capable product is the white-ink generation and white ink controls. While creating print jobs within MelcoRIP, you have the capablity to both automatically or manually generate white-ink underbases. In addition, the ability to export, touch-up and import the automatically generated white separation assures that any artwork scenario can be successfully negotiated using this white ink feature set.

White Layer Generation

The White Layer Generation drop-down specifies which white-ink generation method will be used. The method chosen will depend on the artwork.

The create button initiates the white-layer creating cycle.

White ink density slider adjusts the density of the white layer. Slide to the right for more density, to the left for less density

White Ink Under Black

Under some circumstances, it might be desirable to print white ink under black ink (normally white ink is not printed under black). This slider allows you to specify how much white ink to place under black ink. Normally this will stay at zero.

The Remove Black Ink checkbox will remove black or very dark colors from the color layer of an image when the underbase is created. This may work well when printing on a black product, but black ink may be necessary on other colors. If black ink is removed by mistake, simply uncheck the box and create the white underbase again.

Black Handling

The black-detect threshold allows for adjusting the sensitivity of what level of saturation a composite color is considered black. This slider does essentially the same as the slider in the Printer & Ink Configuration dialog except in the print-from workflow each graphic can use a different black detect threshold.

Auto White Highlight

The density slider in the white highlight applies to the density of the highlight, whether auto-created or manually imported. This is NOT the same as the threshold for the automatically generated white highlight in the print-to workflow.

When the Create White Highlight button is clicked, the software will create a white highlight layer from all the areas where there is only white and no color.

The Import White Highlight button allows for importing an artwork file to be used as the white highlight layer. The graphics geometry of the file must match the color layer (resolution, size horizontal and vertical pixels, etc.).

White Layer Generation

It is important to understand that for a computer to automatically generate a white layer, it must have a way to identify which pixels should have white, white and color or no ink at all. There is no “magic” algorithm which can perfectly generate the white ink every time regardless of artwork. Ultimately, the only absolutely foolproof way is to generate the white ink separation yourself. Having said that, Melco RIP has several automatic and manual white generation features that should cover any conceivable artwork scenario. It is important to know how they work so that the proper method can be employed for a particular graphic. This section will show some samples that can be used as a guide, along with an explanation of each method.

The layer types in available are: Hide

Use Transparency To Detect Background back_to_top_arrow.png

Probably the most versatile method. This method, as the name suggests, uses the transparent background of an image to generate the white. The image MUST have a transparent background for this method to work.

jay_trans_background.png

The original artwork as viewed in a graphics program.
The transparent background is represented by a gray and white checkered background.

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jay_use_trans_white.png

The White Layer is generated when the create button is clicked. Any really dark or black pixels get the amount of underbase specified by the "White ink under black" slider.

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jay_use_trans_preview.png

Using the preview view button, an approximation of the final product can be seen.

Use Background Color back_to_top_arrow.png

Similar to the “Use Transparency” method except that it uses the background color. The color of the background is determined by the upper left pixel. It could be the color of the cotton to be used (yellow, for instance) or a color not used anywhere else in the graphic. Either way, the background color will be “punched out” (removed) from the graphic in both the white underbase and the color layer.

jay_yellow_background.png

The original artwork as viewed in a graphics program.
The background is a solid yellow. To avoid printing a yellow rectangle on the product, Use Background Color will be used to generate the white layer and remove the yellow from the graphic.

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jay_use_back_white.png

The White Layer is generated when the create button is clicked. Any really dark or black pixels get the amount of underbase specified by the "White ink under black" slider.

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When the white layer is created, the background color is also removed from the color layer.

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jay_use_back_preview.png

Using the preview view button, an approximation of the final product can be seen.

100% White Under Any Colored Pixel back_to_top_arrow.png

Places 100% white underbase under any colored pixel. White ink will not be placed under any pure white pixels. This is mostly used for solid artwork. If the artwork has white areas that you wish to print in white, add a small amount of color ink to make the 100% white appear. Adding 1% yellow to the white areas of the bird, for instance, will allow those areas to print. Also, if you use this method on artwork that fades into the background, it might create a white “halo” around the image.

jay_white_background.png

The original artwork as viewed in a graphics program.
The background is a solid pure white, and a slight 1% cyan tint has been added to the white of the bird.

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jay_100_white_white.png

The White Layer is generated when the create button is clicked. Any color pixel gets a solid white underbase. Any really dark or black pixels get the amount of underbase specified by the "White ink under black" slider. Pure white pixels get no underbase at all.

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jay_100_white_preview.png

Using the preview view button, an approximation of the final product can be seen.

Underbase Entire Image back_to_top_arrow.png

Simply puts a white pixel under every pixel in the image, white or otherwise. Used mostly for full-frame photographs, etc.

jay_photo.png

The original artwork as viewed in a graphics program.

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jay_entire_white.png

The White Layer is generated when the create button is clicked. The underbase is a grayscale underbase. Any really dark or black pixels get the amount of underbase specified by the "White ink under black" slider.

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jay_entire_preview.png

Using the preview view button, an approximation of the final product can be seen.

Import From File back_to_top_arrow.png

This method allows the user to import a white layer from a separate file. The image must be of the same size (pixels width and height) as well as depth (bits per pixel). If a color file is imported for the white layer, it will be converted to grayscale then used as the mask.

jay_white_background.pngjay_manual_ubase.png

The original artwork file and manually created underbase file as viewed in a graphics program.

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Clicking on Create will bring up an import graphic window. Navigate to the underbase file created in a graphics program. Click Open".

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jay_import_white.png

The manually created underbase will be brought into the Create Job window. If the pixel dimensions are identical to the color layer, the underbase will line up.

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jay_import_preview.png

Using the preview view button, an approximation of the final product can be seen.

Use Only White Ink back_to_top_arrow.png

This method is used for printing only white ink. A white logo or white text on a dark shirt, for instance. Simply import a file and it will be converted to monochrome and rendered using only white ink.

jays_text.png

The original artwork as viewed in a graphics program.
It is completely done in grayscale and the background is a solid pure white.

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jay_whiteonly_white.png

The White Layer is generated when the create button is clicked. With "Use Only White Ink" selected, clicking Create will also remove the color layer completely.

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jay_whiteonly_preview.png

Using the preview view button, an approximation of the final product can be seen.

Touching Up the White Ink Layer

One of the great features of MelcoRIP is the ability to export the automatically generated white layer, edit it and import it back in.

To illustrate a scenario, the blue jay has been used. In this example, the white of the birds chest is pure white. When saved like this, this file does not have any means for the automatic-white routine to detect where the white should be so some areas that should receive white will not.

jay_white_background.png

The original artwork as viewed in a graphics program.
The background is a solid pure white, as is the white of the bird's chest and face.

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jay_ubase_bad.png

Since it does not have a background, we cannot use the “Use Background” method. Since it does not have a transparent background we cannot use the “Use Transparency” method. Also, because it is not a rectangular image we cannot use the “Underbase Entire Image”. That leaves “100% white under any colored pixel”. The problem is that since it will only put white under any “colored” pixel, it will not put any white where the clouds are and in some areas of the hat. The user could put 1% yellow or cyan in all these areas and it would work fine but for the purposes of this demonstration, the underbase will be created and then edited to be appropriate.

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jay_ubase_preview_bad.png

When previewed, the lack of white ink under the bird's chest and face is evident. To remedy this, the white layer can be exported and edited in an image editing software.

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export_export_white_channel.png

To export the white layer for editing, click on Export > Export White Channel.

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exported_white.pngexported_white_fixed.png

The exported channel can then be corrected in an image editing software. Save the changes.

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jay_ubase_fixed.png

Then, select “Import From File” and import the edited white back into the job.

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jay_ubase_preview.png

Using the preview view button, an approximation of the final product can be seen. Now the bird has white on chest and face. There is no limit on the editing that can be done to the white layer but it does have to remain the exact size as when it was exported.