How to correctly set up white printing – how to prepare your file
In addition to the classic CMYK colors (cyan, magenta, yellow, and black), white ink can also be used on certain materials. This allows for particularly impressive effects to be achieved with transparent or translucent materials such as plexiglass or films.
In order for the white print to be implemented correctly from a technical standpoint, your file must be prepared accordingly.
What does white printing mean?
White printing refers to the use of white ink as a separate printing color. It can be used either across the entire surface or selectively placed under specific areas of your design.
Especially with transparent materials, a white underlayer ensures that colors appear more vibrant and do not translucent.
Can white be combined with CMYK?
Yes. Modern printing systems can apply multiple layers of ink on top of each other.
For example, it is possible to:
-
First print a white layer
-
then to place the CMYK colors on top.
Especially with transparent materials, a white underlayer is useful, as colors like cyan, magenta and yellow can otherwise appear translucent.
What white printing options are available?
Depending on the product, you can choose from different options:
Paint with a layer of white
A white base layer is printed beneath the color layer. The white ink is slightly transparent, but already ensures more intense color reproduction.
If you only want to print white, do not add any color content.
Paint with two coats of white
Here, a double layer of white is applied before the color is printed. This significantly increases the opacity. If only white is wanted, omit CMYK colors.
Day & Night
This option is particularly suitable for backlit applications, such as light boxes. A white layer is placed between two colored layers, ensuring that the image appears vibrant both when illuminated and unilluminated.
How do you create your file for white printing?
The preparation depends on how precisely you want to control the white print.
Automatic options
Completely white background
Your entire design will be overlaid with a white layer. No separate attachment is required in your file.
White among all colored elements
All colored areas automatically receive a white background.
This option is only suitable for vector graphics. It is not recommended for photos or complex raster images.
Please note the minimum color values:
-
Cyan: at least 2%
-
Magenta: at least 1%
-
Yellow: at least 6%
-
Black: at least 1%
Only values above this threshold are reliably detected.
Use white as a solid color (recommended for targeted placement)
If you want to precisely determine the position and opacity of the white ink, define white as a separate solid color.
Here's how to proceed in Adobe Illustrator:
-
Open or create your design.
-
Select the shape that should be printed in white.
-
First, assign a striking color to this shape (e.g., 100% cyan). This is only for visibility and will not be printed later.
-
Open the "Color Swatches" window.
-
Create a new color swatch.
-
Name this color field exactly "White".
-
Set the color type to "Spot Color".
-
Confirm the settings.
-
Save your file as a PDF.
Correctly adjust overpressure
If the white shape is to be placed under a colored shape, it must be set to "overprint". Otherwise, the printing system will only recognize the top layer.
Here's how to activate overprinting:
-
Place the white shape above the colored elements.
-
Mark the white shape.
-
Open the "Attributes" window.
-
Activate "Overprint fill" or – for lines – "Overprint outline".
-
Check the result via "View → Overprint Preview".
If you have used a striking color such as 100% cyan for better visibility, the preview may appear as a color overlay. This is for verification purposes only and does not reflect the final printed result.
Control the opacity precisely
When you define white as a solid color, you can adjust the opacity of individual elements. Reducing the opacity creates transparent or semi-opaque effects.
Useful tip
For reliable operation, it is recommended to work with a defined solid color library. This ensures that the white ink is correctly recognized.