Load the artwork you exported for print, and this checker compares it against your printer specification: total ink coverage, resolution, bleed and the way your blacks are built. Everything runs in the browser, so you can see exactly where the risky areas sit on the page.

What this tool does

Drop in a PNG or JPEG and the checker measures it against your print settings: trim size, bleed, safe margin, required resolution, total ink limit and the CMYK profile you expect the shop to use. The verdict comes back in three steps, from "not ready to send" through "worth checking" to "ready to send", and every warning is filed as critical, worth checking, or background information. Load a whole interior at once and each page is analyzed in turn and listed in a page table. The preview shows the original, a CMYK estimate and a total ink heatmap side by side, and the results export as a JSON, Markdown or HTML report plus a heatmap PNG.

Who it is for

It is aimed at people sending doujinshi, indie comics and zines to a commercial printer, and at anyone printing posters, art prints or merch from digital artwork. Print shops publish a specification sheet with a required dpi, a bleed size and an ink limit, and the usual failure is not knowing whether the exported file meets it until the printed copy comes back wrong.

A last check, right before submission, that the exported file matches the printer specification
Artwork with dark backgrounds or heavy blacks, where too much ink can be laid down at once
Covers where text, logos or a QR code may sit too close to the trim line
Full-bleed pages, to confirm the artwork really does run past the trim edge

How to use it

Pick the closest use preset: doujinshi color cover, doujinshi color interior, monochrome comic interior, merch and posters, or a custom print shop spec.
Adjust the trim size, bleed, safe margin, required resolution and total ink limit to match the numbers on your printer specification sheet.
Load the artwork by dragging and dropping it or picking it from the file dialog. To check a whole interior, select every page file at once.
When several pages are loaded, click a row in the page table to switch the detail view and the previews to that page.
Read the verdict at the top of the diagnosis panel, then work down the warnings from the critical group.
Use the total ink heatmap in the preview to find the red areas on the artwork itself.
Export a JSON, Markdown or HTML report, or the heatmap PNG, if you want a record. The Markdown export is written as a preflight checklist, so you can hand it straight to a collaborator or paste it into a chat.

What each setting means

Use preset: Five starting points. Choosing one switches the trim size, required resolution, bleed and total ink limit together, so you can start from something close and then adjust.
Bleed: The extra artwork that extends beyond the trim size. It exists so that a slight drift in the cutting does not leave a white strip of paper at the edge. Three millimetres is the usual request.
Safe margin: The band just inside the trim line where you should avoid putting anything important. If a lot of high-contrast detail lands in that band, the checker raises a warning.
Required resolution: The dpi your printer asks for, commonly 350 dpi for colour work and 600 dpi for monochrome comic pages. Combined with the trim size and bleed, it gives the pixel dimensions your export has to reach.
Total ink limit (TAC): The ceiling on C plus M plus Y plus K, expressed as a percentage. Going over it means the ink does not dry in time, which leads to set-off, sticking and smudged pages. Coated stock is typically 300 to 320 per cent; matte, uncoated and newsprint stock is lower.
CMYK profile: The colour behaviour used for the estimate. It changes how the black plate is generated and how far out-of-gamut colours are pulled in. As the "approx." in each name says, these are approximations of the named standards, not the ICC profiles themselves.

Reading the results and fixing them in Clip Studio Paint

Items under "Critical" are the ones likely to cause visible trouble on press if you send the file as is. Start there.
The profile item under "Background" is always present. It is the note explaining that this is an approximate estimate, not something to fix.
Max TAC, average TAC and the area over the limit tell you how heavily ink is being laid down.
Rich black and four-color black measure how much of the page uses black built from several plates. It is often fine across a large background, but on thin lines and small text a slight misregistration shows up as coloured fringing.
RGB shift avg / max is the distance between the colour you saw on screen and the estimated CMYK colour. The larger it is, the more your vivid blues, greens, purples and pinks will dull down.
If the resolution falls short, re-export from Clip Studio Paint at a canvas size that covers trim plus bleed at the required dpi. Changing the dpi field alone in the export dialog does not add detail that was never drawn.
If the ink coverage is too high, lower the saturation in the offending areas, or rebuild the black so that it leans on the K plate instead of stacking all four.

How the numbers are calculated

The CMYK estimate is a simple model that assumes sRGB input. Each channel is mapped to a dot area as (1 - R/255) raised to a power, where the exponent is the gamut compression of the selected profile. The black plate is the minimum of C, M and Y multiplied by that profile black generation amount, and total ink coverage is the plain sum of C, M, Y and K. The CMYK estimate preview converts that back to RGB with an ideal ink model, R = 255 x (1 - C) x (1 - K), which is why it reads as a soft proof of the shift rather than a colour-managed match. Estimated dpi comes from dividing the pixel dimensions by the physical size of trim plus bleed. Missing bleed is detected from the proportion of white or near-transparent pixels in the outer band of the image.

Accuracy, and what is out of scope

This tool is in beta. It performs an approximate CMYK estimate inside your browser and does not read an embedded ICC profile or run a strict, colour-managed conversion. Strict ICC conversion, PDF/X validation, .clip file parsing and automatic correction are all out of scope. Treat the output as a way to catch obvious problems early, not as a colour proof.

The colour you finally get depends on the press, the paper and the ink at your print shop. For the real decision, check your CMYK export settings in Clip Studio Paint against the ICC profile your printer specifies.
The bleed and safe area checks assume the outer edge of the loaded image is the bleed area. If you exported at exactly the trim size, the bleed warning has nothing meaningful to measure.
Analysis runs on the RGB image, so it cannot judge whether a monochrome page has been correctly reduced to two tones or converted to halftone screening.

How your images are handled

Loading and analysis both happen inside your browser. Your artwork is never uploaded, and neither are the reports you export. Only the print settings are kept, in the browser local storage, so that the tool remembers your printer specification next time. The images themselves are not stored and disappear when you close the page.

Frequently asked questions

If the verdict says ready to send, is the file guaranteed to print correctly?

It means that, within the print settings you entered, nothing measurable from the pixels came back as a problem. Because the CMYK conversion is an approximation, the final colour decision still belongs to your printer specification and a proof.

The CMYK estimate does not match my printed copy. Why?

The estimate is a formula, not an ICC transform, so absolute colours will not line up. Use it to see which colours shift, in which direction, and by roughly how much, rather than as a colour-accurate soft proof.

Can I check a whole book at once?

Yes. Select several files in the loader and each page is analyzed in turn and collected into a page table with the file name, verdict, estimated dpi, max TAC and the number of critical items. Only the selected page keeps its pixel data, though, so only that page is re-judged automatically when you change the print settings. Other rows are marked as being from the settings at load time; press the re-analyze button to bring them up to date.

Does it work for monochrome comic pages?

It does. The monochrome comic interior preset uses 600 dpi and a 250 per cent ink limit, which is a common request for interior pages on uncoated stock. Keep in mind that the analysis reads the RGB image, so it will not tell you whether your tones are true halftone screening or greyscale.

What total ink limit should I enter?

Use whatever your print shop publishes. If nothing is stated, 300 per cent is a safe starting point for coated stock, and around 250 per cent suits uncoated or newsprint-like paper, where ink soaks in and dries slowly.