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Guided workflow variation

From customer art to film,in one separation app.

Underbase is a Windows app that opens the artwork customers send, sorts it into ink plates, builds a choked white underbase, and writes halftone TIFFs, a true-size film PDF, and a production ticket. It is bought once in the Microsoft Store.

For limited-color apparel jobs, Underbase takes artwork from file to film in one app: confirm the inks, choke the base, check the plate count, and generate.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Full Underbase overview
One-time purchase No telemetry Local-first

windows · runs on your pc · no account · nothing uploads · 15-day free trial

If this sounds like your week

Separations usually happen inside a design program.

In many small shops, separating a logo means opening it in a general design program, selecting one color at a time, saving each selection as its own channel or layer, then building registration targets and a white base by hand. Some owners add a separation plugin on top of that host, often sold as a yearly license. Others send the art to an outside separator and wait a day or two for files to come back, paying per design.

Where tooling usually breaks

Each manual step is a chance to burn the wrong screen.

A missed shade becomes a gap on the shirt. Targets nudged by a few points drift between frames. A positive printed at the wrong scale is not discovered until the squeegee is already moving. Every mistake costs emulsion, reclaim time, and a slot on the press schedule, and the customer still expects the order on the promised date.

Where Underbase lands

One app from the customer's file to the film.

Underbase replaces that routine with a single window. Drop in the file, and it proposes the inks, groups anti-aliased edges, and leaves the background unprinted. You confirm names, order, and which colors sit on white, while a budget tile counts screens. One click on Generate underbase pack writes 1-bit TIFF plates, unscreened channels, the film PDF, a ticket, and a preview into one job folder.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Learn more about Underbase

windows · runs on your pc · no account · nothing uploads · 15-day free trial

What you get

Feature highlights

Spot or index separation from the files customers send

PNG, TIFF, JPEG, BMP, GIF, WebP, SVG, PDF, and Illustrator (.ai) files, with close shades grouped, the background left unprinted, and shaded art dithered between a fitted set of inks.

A choked white underbase

built from the inks you tick, pulled in from 0 to 3 mm in 0.05 mm steps, with dark inks printing straight on the shirt and a preview on seven garment colors.

Trapping in one click

spread or choke any ink from -3 to +3 mm, or apply the default trap to every ink so lighter colors tuck under the darkest.

Halftones tuned to your press

screen any plate at your ruling, angle, and tint, take a ruling suggested from the mesh, thin halftones for measured dot gain, and check the output dots before film.

A plate budget you can see

Underbase counts the underbase and every printing ink against the screens your press holds, holds generation until the job fits, and merges inks to fit in one click.

True-size film and a production ticket

a film PDF with identical registration marks and plate labels, one plate per sheet or ganged, 1-bit TIFFs at up to 1440 dpi, and a ticket as PDF and JSON.

Especially when

  • Turn a customer PNG, JPEG, SVG, PDF, or Illustrator file into one plate per ink without selecting colors by hand in a design program
  • Build a white underbase for dark shirts that is choked so it never shows at the edges, and keep dark inks off it
  • Know the plate count before burning a screen, and merge inks to fit the screens the press holds
  • Print film positives at true size with registration marks and plate labels, plus a production ticket, without sending the job to an outside separator

Who benefits

Real-world scenarios

A two-press shop that outsources its seps

The shop sends every multi-color job to an outside separator and waits for files to come back, which pushes rush orders out by a day and adds a charge to every design.

With Underbase on the front-desk PC, the owner opens the customer's PNG, confirms three inks, ticks which ones sit on the underbase, and generates the film pack in the same sitting. The film prints in-house, and the ticket goes to the press with the screens.

Checking the app against a past job

Before buying, a press operator wants to compare Underbase output with film the shop already burned for a repeat customer, including the underbase choke and the print order.

During the 15-day free trial, the operator opens the old artwork, sets the same print width and choke, and prints the film PDF. The registration marks, plate labels, and coverage on the ticket can be checked side by side with the old positives.

A new hire learning separations

A new employee knows the press but has never separated art. The owner wants the newcomer to prep simple jobs without learning a full design program first.

Underbase lists every ink with its coverage, shows each plate on its own, and flags dark inks left off the base and white that looks like background. The newcomer confirms, generates, and hands over a ticket the owner can sign off.

Deep dive

What to check before you choose screen printing separation software

The files customers really send. Orders arrive as PNG logos, phone-exported JPEGs, TIFFs from a print shop, SVG and PDF exports, and Illustrator files. Underbase opens PNG, TIFF, JPEG, BMP, GIF, WebP, SVG, PDF, and Illustrator (.ai) files, rasterises vectors at 300 dpi at their true size, and reads the resolution tag of raster files so the print size starts out right. When a file carries no tag, it says so and lets you set the source resolution or simply type the print width.

Spot and index in the same tool. Flat logos want one clean plate per ink. Shaded art, soft shadows, and gradients want index separation, where every pixel goes to the nearest ink and the leftover error is diffused into a dither. Underbase does both, switches to index mode when it detects shading, and lets you change the mode from the Separation list at any time.

Control over every plate. Automatic ink detection is a starting point, not the last word. In Underbase you rename inks or pick a stock name, change the color, merge one ink into another, switch Print off for anything that is really the shirt, and move plates up or down to set the print order. Reduce to merges the closest inks in spot mode or re-fits the palette in index mode.

Underbase and trapping. For dark garments, tick UB on each ink that needs white under it and set the choke; dark inks are left off the base by default and print straight on the shirt. Spread or choke any single ink, or use Apply to all inks to spread every ink except the darkest by the default trap.

Halftones that match the press. Any plate, including the base, can be screened at the ruling, angle, and tint you set, and Suggest ruling from mesh picks a ruling from the mesh count. Dot gain compensation thins halftone plates by the mid-tone gain you measure, and the Output dots preview renders the plate as the film will carry it.

A plate budget you can see. Set Screens available on press and the budget tile counts the underbase plus every printing ink. A job that needs more screens than the press has is held back from generation, and Merge inks to fit the budget brings it in with one click.

Film that comes out the right size. The film PDF is true size on Letter, Legal, Tabloid, Super B, ANSI C, A4, A3, A3+, A2, or a custom sheet, with identical registration marks, center ticks, and a label on every plate. Mirror flips it for emulsion-down output, and small designs gang several plates on one sheet.

A ticket for the press crew. Every pack can include a production ticket as PDF and JSON with the print order, mesh, offsets, coverage, garment, quantity, due date, notes, and sign-off boxes.

Try it on your own art. The Microsoft Store runs a 15-day free trial, so separate a job you have already printed and compare the film before you buy.

How it is built

Built for the press, not the design studio.

The press sets the limits

You enter the screens your press holds, the mesh, and the dot gain you measure. Underbase counts every plate against that budget and thins halftones to match before any film is written.

Film at true size

Every plate lands on the sheet at true size with identical registration marks, center ticks, and a label naming the job, plate, ink, screening, offset, and mesh.

Nothing uploads

Underbase runs entirely on your PC with no account, no telemetry, and no network connections. Customer artwork is only read. One-time purchase in the Microsoft Store.

Head-to-head

How Underbase compares

Feature Underbase Separating by hand in a design app Separation plugin Outside separation service
Inks found for you Yes, with close shades grouped and the background left unprinted Selected color by color Varies by plugin Done by the service
Choked white underbase Built from the inks you tick, choked from 0 to 3 mm Merged and shrunk by hand Often included Included in the order
Plate count checked before output Yes, the plate budget counts every screen before generation Counted by eye Varies by plugin Agreed with the service
True-size film with registration marks Film PDF with identical marks, one plate per sheet or ganged Marks placed by hand Depends on the host program Delivered as files
Production ticket PDF and JSON, written with the film Written separately Varies by plugin Varies by service
How it is paid for One-time purchase in the Microsoft Store Design app license or subscription Plugin license on top of a host program Per design

FAQ

Straight answers—no glossary dump

What should screen printing separation software do?

It should split the artwork into one plate per ink, give you control over which colors become inks and in what order they print, build a white underbase for dark garments, handle trapping, and output film at true size with registration marks. Underbase does all of that for limited-color apparel art on Windows, and it also checks the job against your plate budget and writes a production ticket for the press.

Can I separate colors for screen printing without a design app?

Yes. Underbase opens the customer's file directly, finds the inks, and writes the film, so there is no host program to run first. Open the artwork, confirm the inks in the Inks and plates list, tick UB on the inks that need white under them, check the plate budget, and choose Generate underbase pack. The film PDF, 1-bit TIFFs, channels, and ticket land in one job folder.

Which separation mode should I use?

Use Spot (flat colours) for clean logos and vector-style art, where every exact color belongs to one ink and anti-aliased edges are shared between neighbors. Use Index (dither soft edges and gradients) for JPEGs, soft shadows, and gradients; every pixel goes to the nearest ink and the shading becomes a dither. Underbase switches to index mode on its own when it detects shading, and you can change it in the Separation list.

What artwork files does Underbase open?

PNG, TIFF, JPEG, BMP, GIF, WebP, SVG, PDF, and Illustrator (.ai) files, opened with Open artwork, by dropping the file on the window, or from Samples. Vector files are rasterised at 300 dpi at their true size. A raster file's resolution tag sets the print size; when a file has no tag, Underbase uses 300 dpi, flags it, and lets you edit the source resolution or type the print width you want.

Does my customer's artwork stay on my PC?

Yes. Underbase runs entirely on your PC. There is no account, no upload, and no telemetry, and the app makes no network connections. It reads the artwork you open, writes each job to a folder inside the output folder you choose, and keeps its own settings in local app data. Jobs save as .underbase files you can reopen for a repeat order.

How do I get Underbase, and is there a trial?

Underbase is a one-time purchase in the Microsoft Store, and the listing shows the current price in your currency. The Store runs a 15-day free trial, so you can separate a job you have already printed, or one of the six bundled samples, and compare the film with what you burned. The Store installs and updates the app. It runs on Windows 11 version 24H2 or later on x64 PCs.

Related pages

Flat-color tee art, split into one plate per ink. A white underbase for dark shirts, choked so it stays hidden. Film positives at true size, with the dots you set. Gradients and soft shadows, printed with a handful of inks.

Customer art in.
Press-ready film out.

Underbase separates flat and shaded art into spot inks, builds a choked white underbase, traps colors in one click, keeps the job inside your plate budget, and writes true-size film with registration marks and a production ticket. Everything runs on your PC, and the Microsoft Store runs a 15-day free trial.

Pay once. Own it forever.

One-time purchase on the Microsoft Store · No subscription · Instant install

Get it from Microsoft

Buy through the Microsoft Store—instant install, automatic updates, and a Microsoft receipt for easy expensing. No account needed on our site, and no subscription on Store purchases.

Open full product page

Illustrator is a trademark of its owner, registered in the U.S. and other countries. Underbase opens Illustrator (.ai) files as an input format and is not affiliated with or endorsed by the trademark owner.

Technical specifications

Technical specifications for procurement

Spec Implementation
Data Sovereignty Reads only the artwork you open or drop on the window and never writes to it; writes each job (film PDF, TIFF plates, channels, ticket, preview, and .underbase job file) to a folder inside the output folder you choose; settings stay in local app data on this PC
Telemetry Status None; no account, no upload, no telemetry, and no network code in the app
Core Runtime .NET 10 and WPF, self-contained, distributed through the Microsoft Store as an MSIX package; separation, halftoning, TIFF, and PDF output run in the app’s own engine, with PDF and Illustrator (.ai) pages rendered by a bundled PDFium engine
Network Requirements Fully functional offline; the app makes no network connections and nothing is uploaded
Deployment Compatibility Windows 11 version 24H2 or later (10.0.26100), x64; 8 GB RAM recommended for very large artwork, about 400 MB of disk; one-time purchase in the Microsoft Store with a 15-day free trial
Inputs PNG, TIFF, JPEG, BMP, GIF, WebP, SVG, PDF, and Illustrator (.ai) files; vectors rasterised at 300 dpi at true size; print size from the file’s resolution tag or a print width you set, in inches or millimeters
Separation Spot mode (one ink per flat color, close shades grouped, background left unprinted) or index mode (error-diffusion dither between a fitted ink set, dither strength 0 to 100); reduce to 1 to 16 inks; rename, merge, reorder, or switch off any ink
Underbase and traps White underbase from the inks you choose, choke 0 to 3 mm; spread or choke per ink from -3 to +3 mm; one-click trapping of every ink under the darkest; suggested print order with highlight white
Screening Solid or halftone per plate at 10 to 120 lpi, any angle, with tint; ruling suggested from mesh count; dot-gain compensation from 0 to 50 percent; output dots preview at the output resolution
Outputs True-size film PDF with registration marks, center ticks, and plate labels, one plate per sheet or ganged, mirror for emulsion down; 1-bit CCITT G4 film TIFF per plate at 600, 720, 1200, or 1440 dpi; unscreened 8-bit channel TIFFs; production ticket as PDF and JSON; preview PNG; .underbase job file
Film sizes Letter, Legal, Tabloid, Super B, ANSI C, A4, A3, A3+, A2, or a custom sheet up to 60 x 120 in; direct printing to any Windows printer