DTF Glossary
Varnish channel
A varnish channel is a separate grayscale production plane that tells a UV-capable workflow where to place clear coating. It is not process colour, transparency, or white underbase. Its coverage, name, polarity, and optional outward spread must be validated against the exact RIP, printer, ink, film, curing, and transfer process.
In practice
Spread grows the varnish mask outward; choke shrinks a white mask inward. Applying the wrong operation can leave an uncovered edge or place coating beyond the intended design.
For a UV workflow, obtain the clear-ink source, channel name, polarity and print order from the equipment supplier. NestSheet’s current garment-DTF production preset writes CMYK plus one W1 white channel for MainTOP.