Concept
Knockout
An area of a design where the white underbase is removed so the substrate color shows through the print.
Definition
Knockout is a print technique where the white underbase is removed in a defined area so that the substrate color shows through the printed image. On a dark garment, a knockout area appears as the garment color rather than as printed ink. Knockouts are used to integrate the garment color into the design as a deliberate visual element, to reduce ink coverage on large solid areas for a softer hand feel, and to add transparency effects in halftones and shadows. In the DTF workflow, knockouts are defined by the alpha channel of the submitted artwork file. Areas with zero alpha receive no white and no color.
Related Terms
White Underbase
A layer of white ink printed beneath color ink so the design reads correctly on dark or colored fabric.
Alpha Channel
The transparency channel in a raster image that controls which pixels print and which stay clear.
Transparent PNG
A PNG file with a transparent alpha background so only the design prints and the surrounding film stays clear.
Color Separation
Splitting an artwork file into individual ink channels for each color the press will print.