Good to know before you screen

True binary, 1-bit-per-channel separations: every channel is reduced to dots that are either fully on or fully off, placed by the chosen FM / stochastic screen. That's the form a RIP or imaging device expects for final output.

Yes — screening is applied in place to the active document. Its channels are replaced with the halftoned result, and for CMYK the document is flattened as part of the write. It all happens as a single undo step, but you should still duplicate your file first if you want to keep the continuous-tone original.

The whole operation is one undo step, so Ctrl/Cmd+Z reverts it within the session. For a durable original, work on a copy (Image ▸ Duplicate…) rather than relying on undo history.

Platesetter for high-resolution imagesetter / CTP output where crisp, dispersed dots matter most. Inkjet for flatbed and wide-format inkjet, where the joint 16-state overprint screen and optional dot-off-dot mode model how those devices actually lay ink. See Features for the details.

RGB is read directly and its R/G/B channels are treated as the C/M/K roles (yellow ignored). Grayscale is treated as CMYK's K channel and run through the Platesetter screen. Full four-ink screening needs a CMYK document. See How to use for the per-mode breakdown.

Photoshop's UXP imaging API can't read or write CMYK pixels directly, so the plugin splits the document into four temporary grayscale channels, screens them together, and writes the binary planes back. The brief flashing is inherent to that Split Channels step and can't be suppressed — the temp docs are closed automatically when the run finishes.

Yes. With the Inkjet engine you can split each process color into up to three density levels — dark, light, and light-light — matched to the lighter inks modern Epson desktop photo printers carry (Light Cyan, Light Magenta, Light Black, Light Light Black). Each shade becomes a pure single-colorant spot channel. Set the level count per channel to match your printer's ink set (e.g. an Epson P600: C 2, M 2, Y 1, K 3). See light-ink separations.

The output is a clean contone separation — a faithful preview of the ink split showing which inks are used and at what coverage — created as a single undo step. Spot levels are an Inkjet-engine control; the Platesetter engine locks every level to 1.

No. A grayscale document's single channel is the K role, which carries no inter-channel hysteresis. Only Ink limit applies there; the hysteresis scalars have no effect.

It scales every channel's coverage down before screening, capping the maximum ink laid down so you can stay within a press's total-ink limit. 100% leaves the full tonal range untouched.

The screens are ported from the LAULenticularRIP desktop application — the same dot-placement models, green-noise / stochastic dispersion, and overprint screening — delivered as a Photoshop plugin so you can apply production-grade screening without leaving Photoshop.