Screen Printing Production Art and Color Separation in Illustrator

Vocabulary terms and definitions covering vector preparation, underbasing, trapping, attributes, and color separations for screen printing in Adobe Illustrator.

Outline Mode

An Illustrator view mode (accessed via Command Y on Mac or Control Y on PC) that displays the underlying vector paths and reveals hidden artwork not seen in the preview.

Spot Color

A swatch color type defined so that all assigned artwork outputs to a single dedicated color channel rather than a combination build of CMYK process inks.

Separations Preview

An Illustrator menu that allows screen printers to view spot color channels independently and verify that elements are assigned to their proper separation plates.

Overprint Preview

A display mode in Illustrator that visually previews how overlapping inks will interact, allowing users to verify knockouts, trapping, and layer transparency before printing films.

Merge (Pathfinder)

A Pathfinder operation used during file cleanup to eliminate underlying hidden vector shapes across selected artwork.

Paste in Place

A command executed via Shift + Command + V (Mac) or Shift + Control + V (PC) that places copied objects into a targeted layer at the identical spatial position.

White Underbase

A foundational white ink layer printed beneath lighter colors (such as light blue and medium blue on a medium gray shirt) so they stay vibrant on the garment.

Manual Press Separation

A separation setup where white functions as both the underbase and final design color (such as the seagull), printed twice with a flash cure in between on a manual press.

Automatic Press Separation

A separation setup requiring a fifth screen because the white underbase prints only once, and a second separate top white screen prints later at the end of the job.

Overprint Fill

An attribute assigned to a shape or layer fill (such as a top-stacked white layer) to keep it from knocking out the other color channels beneath it.

Butt Registration

A condition where adjacent colors meet exactly edge-to-edge without any intentional overlapping or trap allowance.

Trapping

The deliberate creation of a small overlap between touching colors to prevent the white underbase or shirt fabric from peeking through if the press goes slightly out of registration.

Overprint Stroke

An attribute applied to an outline or stroke so that it prints on top of underlying colors instead of knocking them out, creating a functional trap.

Round Join

A stroke corner setting applied when creating traps to ensure smooth, clean corners on the overlapping stroke boundaries.

Registration Color

A specialized swatch that visually appears black and automatically prints on every single film separation plate in the print run.