Every reprint looked fine on screen.
That is what preflight is for — the faults you cannot see

A file that opens is not a file that prints. The things that cost a rerun are invisible in a viewer: ink that stops at the knife, a picture that is 96 dpi at the size it was scaled to, a font that was never embedded, white set to overprint. This reads the file itself — the boxes, the resources, the matrix every image is placed with — and then renders each page to answer the one question the structure cannot. 完全免费。 真的免费。

Free, no account.
Every check and every report is free from the first open — no sign-up, no credits, no limit on files.
Nothing is uploaded.
The file is read in your browser and stays there. A job on its way to press is somebody's unreleased packaging.
Your printer's figures.
Bleed, resolution and the finest line are yours to set. A check whose threshold you cannot see is an opinion.
Measured, not guessed.
Resolution at the size the image is actually placed, matrices and nested forms included. Line width in millimeters after every transform.
The check nobody else runs.
Whether the artwork really carries past the trim — answered by rendering the page, because the structure cannot say.
A report to send on.
The findings, the pages they are on, and the thresholds behind them, as a PDF.

What it checks

The faults that survive a look at the screen

Every one of these opens cleanly in a viewer and comes back wrong from the press.

Bleed and boxes

Where the knife falls, and what is past it

  • Media, crop, trim, bleed and art boxes, in millimeters
  • How much paper stands outside the trim, side by side
  • Whether the ink actually carries past the knife — rendered, not assumed
Open
Resolution

Every picture at the size it is used

  • Effective dpi from the placement matrix, not from the file's own size
  • Followed through nested forms, where the scale is easy to lose
  • Wanted and reprint thresholds, both yours to set
Open
Fonts

Fonts that will still be there at the RIP

  • Embedded, subset, or named and missing
  • Type 3 fonts, which are drawings rather than outlines
  • Small text set in more than one ink, which fringes on any press
Open
Color

The inks the job will actually run

  • RGB in a four-color job, named by page
  • Every spot ink in the file, listed by its own name
  • Output intent — the printing condition the file claims
Open
Lines and overprint

What is too fine, and what will vanish

  • The finest stroke in millimeters, after every matrix
  • Zero-width lines, which mean “thinnest the device can draw”
  • Overprinted white, which shows on screen and prints as nothing
Open
The report

Something to send with the file

  • Errors, warnings and notes, ranked and counted
  • The pages each one is on, runs collapsed
  • The thresholds it was all measured against, printed alongside
Open

What it can do

What is read, what is measured, and what is reported

Two readings of the same file: the structure, and the page as it renders.

01

Geometry

Where the job finishes.

  • All five page boxes, per page, in millimeters
  • Bleed measured on each side separately
  • Whether artwork reaches into the bleed, by rendering
  • Mixed finished sizes across one file
  • Page rotation, and pages with nothing on them
02

Content

What is on the pages.

  • Effective resolution of every placed image
  • Nested form XObjects followed, matrices composed
  • Fonts: embedded, subset, Type 3, or missing
  • Stroke widths in millimeters after every transform
  • Inline images and stencil masks told apart from artwork
03

Color

What it prints in.

  • Device spaces and ICC spaces, by their component count
  • Separation and DeviceN inks, named
  • RGB in a CMYK job, or the other way around
  • Small text set in more than one ink
  • Overprint, including white set to overprint
04

The report

What you send on.

  • Errors, warnings and notes, counted
  • Page lists with runs collapsed — 1–8, 10–12
  • A page-by-page table: size, bleed, images, worst dpi, fonts, finest line
  • The thresholds every check used
  • A PDF, in the same house style as the cutting guides

How it works

Drop the file, set your figures, read the list

The file is read in your browser and goes nowhere.

1

Drop the PDF in

It is parsed on your machine — structure first, then each page is rendered for the checks that need a picture.

2

Set your rules

Bleed, wanted resolution, the finest line your process holds, and whether the job prints in four inks or for a screen.

3

Read what came back

Errors first, then what needs a decision, then what is merely worth knowing. Each one names the pages it was found on.

4

Send the report

A PDF with the findings and the thresholds behind them — which is what ends the argument about whose fault it was.

Where it is used

Before the file leaves, and when it arrives

The same list, read from both ends.

Before you send to print

Five minutes against a week: the faults that cost a rerun are all here, and all of them are cheap to fix while the layout is still open.

Packaging artwork

A dieline job lives or dies on the bleed and the trim box. Both are measured here, per side, per page.

Taking files from a client

A list of what is wrong, with the pages and the figures, is a better answer than “it will not print” — and it arrives in a minute.

Certificates and security work

Hairlines and overprint are the whole trade there, and both are invisible until the sheet comes off the press.

Photo-heavy work

Resolution at the placed size, through every scale and every nested form — which is where a picture quietly becomes 90 dpi.

Archives and reprints

An old file that printed once will not necessarily print again. This says what it depends on before the plates are made.

Questions

What it does, and where it stops

Check the file before the plates are made

Bleed, resolution, fonts, color, hairlines and overprint — measured against your own figures, in your own browser.