PatchForge — Spot Channels & Separated TIFFs

  • Can I have more than white and varnish?

    Yes — anywhere from one to eight channels. The default is two, named White and Varnish, and you can rename any of them. The name is what your RIP separates on, so use whatever your ink setup expects. Each channel also gets a preview colour, which is purely how Photoshop tints it on screen and has...

  • Does the preview colour of a channel matter?

    No. It is screen-only metadata for Photoshop's Channels panel. What the RIP actually reads is the channel data and its name, plus the order the channels sit in. Pick whatever colours make the plates easiest to tell apart.

  • How do I choose which area gets the white or varnish?

    Pick All artwork for every non-transparent pixel, which is what most jobs want. Or pick Colour range to target a specific colour with a tolerance slider — and you can invert that to select everything except that colour. Transparent areas are never selected in either mode, so spot ink never lands ...

  • What are spot channels and why would I want them?

    A spot channel is an extra ink plate alongside the normal CMYK ones — most often white (an underbase so colour pops on dark material) and varnish or gloss. Your RIP separates them as their own inks. PatchForge can build the separated TIFF for you instead of you doing it by hand in Photoshop.

  • What does it actually do?

    It converts your artwork to CMYK through a real ICC colour profile, builds the spot plates from a selection you control, and writes a single layered TIFF that Photoshop and your RIP both read correctly — CMYK plus however many named spot channels you asked for. It replaces the manual routine of c...

  • What is the contraction setting for?

    It pulls the spot plates in from the edge so white or varnish never prints past the cut line — the same thing as Select ▸ Modify ▸ Contract in Photoshop, and it matches Photoshop exactly. Enter the amount in pixels, millimetres, or inches; it shows you the millimetre equivalent as you type. 1px a...

  • Where do I find it?

    Two places. In the Patch Builder: Export ▾ → "Spot channels (TIFF)…". In the Gang Sheet Builder: the "Create spot channels (TIFF)" button under Quick export. Both open the same dialog.

  • Which colour profile does it use?

    It defaults to U.S. Web Coated (SWOP) v2 — what Photoshop's North America Prepress setting separates to — using Relative Colorimetric with black point compensation, the same pairing Photoshop uses. Thirteen other profiles are bundled (GRACoL, FOGRA, Japan Color, uncoated variants), and you can lo...

  • Why is the TIFF so large?

    It is uncompressed CMYK plus your spot plates, which is exactly what a RIP wants — around 52 MB for a trimmed 12×24" sheet, more for bigger ones. The dialog warns you before exporting anything unusually large. The file is built in your browser and downloaded straight to you; it is never uploaded ...