How does White Underpin work?
Printing CMYK ink directly onto a transparent material will result in the colours having a translucent “see-through” effect. This means you will still be able to see elements behind the material and the printed colours will not be opaque.
White underpin is a process where a white layer is applied directly to the material first before the CMYK ink is printed on top. This allows the colour to print directly onto the white underpin and acts like a barrier to the light giving the elements a solid opaque finish.
This can be applied to a number of transparent materials such as stickers and vinyl. When designing your artwork, please follow our White Underpin instructions here to ensure that your design is set up correctly for printing.
White underpin with mirrored printing.
If the desired finish is to have the vinyl/sticker be applied onto a glass/window surface from the inside with the intention to be viewed from the outside, then white underpin can still be used in conjunction with a mirror print preference. The printing process is just a slightly different order. The white underpin is still applied behind the CMYK print, but the sticky adhesive is applied on the face of the print. This allows you to stick the face of the vinyl directly onto the glass surface and the back of the sticker will have the white underpin. Meaning when viewed from the outside of the window, the vinyl will be opaque and clearly visible.