CalderaSubmit (Sign and DTF) - White undercoat

This article explains how to generate a white undercoat beneath printed colors when using a printer configured with white ink.

Access white settings

White settings are configured at the preset level. To display these settings:

1. When you create or edit a device, configure a Custom Inkset that includes White undercoat ink:

   

2. In the preset's Main settings, select a Color mode that includes white, such as CMYKW. The White settings section then appears below the color-mode options.

Select a strategy

Select the strategy used to generate the white undercoat.

Color T-shirt

Use this strategy for films and other transparent media.

It generates a white undercoat beneath colored areas, but not beneath black or fully transparent areas.

Transparency

Use this strategy for transparent media.

It generates a white undercoat beneath colored areas while leaving fully transparent areas unprinted.

Settings available with Color T-shirt

Minimal white and Maximal white

Set the minimum and maximum white-ink coverage for the undercoat. Values are expressed as percentages and default to 0% and 100%.

Use these settings to fine-tune ink adhesion and print feel after evaluating a printed sample.

• Minimal white: Set a minimum white-ink coverage when the media requires a minimum amount of white ink to support the adhesion of other inks.
• Maximal white: Reduce the maximum white-ink coverage to lower the total ink quantity and improve the feel of the print.

Opacity reduce coefficient

Use this setting to reduce white halos caused by residual low-opacity pixels in poorly prepared transparent files. Enter a coefficient of up to 10 to control the strength of the opacity reduction.

Settings available with Transparency

White amount

Set the white-ink coverage generated for transparent media. Enter a value from 0% to 100%.

The white amount is applied according to the image’s transparency values to create white ink beneath the color layer:

• If an image pixel has 50% transparency, the white ink beneath that pixel is 50% of the selected White amount.
• If an image has no transparency, the selected White amount is generated beneath the entire image.

Settings shared by both strategies

White highlight

Available in CalderaSubmit DTF v2.2 and later.

Set the percentage of white ink applied to pixels that meet the White Highlight condition. For example, set 100% for full white-ink coverage or 50% for half coverage.

During print or layer previews, pixels with no color value (0%) have their white undercoat increased to the value set in the White Highlight field. Pixels with at least one color channel above 0%, excluding alpha, use the value determined by the selected generation strategy.

White highlight color threshold

Available in CalderaSubmit DTF v2.2 and later.

This field provides precise control over white-ink application based on color presence. It defines a color-intensity threshold, expressed as a percentage, below which the white undercoat is intensified.

White as transparency

White as transparency gives you more control over white-undercoat generation when printing PDFs with spot colors.

When enabled, the software treats white or low-color areas as transparent, so no white undercoat is generated in those areas.

White as transparency color threshold

Sets the minimum ink quantity required for the software to apply white undercoat ink. Adjust the threshold percentage to fine-tune the amount of ink on top required before the undercoat is generated.

For example, a low threshold applies the white undercoat to light colors, while a higher threshold ensures that only more saturated colors receive it.

Spread (+) / Choke (-)

White ink can spread into the media or become visible around the edges of colored areas. Use Spread with a positive value or Choke with a negative value to adjust the size of the white undercoat and reduce these effects.

Spread	Choke
Expands the white-undercoat edges	Reduces the white-undercoat edges

Smart choke

Enable Smart choke to automatically remove white-undercoat pixels that are not covered by color. This helps prevent visible white outlines or halos around colored areas when slight print-registration misalignments occur.

• Enabled: Removes white-undercoat pixels in areas without color above them.
• Disabled: Keeps the white undercoat at its original extent. This may result in visible white edges if the white and color layers are not perfectly aligned.