Transparency vs White
Preparing vector files using white as color or as transparency (knock-out).
When we prepare vector files for color separation we need to know if the white areas on the graphic will need to be considered as white color ( as in white ink) or if these white areas actually represent absence of color / transparency: a knockout area that allows the background to show through, e.g. the color of the shirt being printed.
How the white areas are created on a vector file, either as white color or as transparency, is important to many processes. For example, spot color printing requires that a color number be assigned to the white areas in order for the white to be included as one of the colors in the color separation process. In vinyl-cutting, if a color design is going over a white background, any white object on the vector file needs to be omitted, otherwise the sign machine will cut out the white shapes when they are not needed.