What Print Prepper does: bleed, crop marks and a print-ready PDF

Customer files turn up wrong in one of five ways: too small, no bleed, wrong shape, wrong details printed on the artwork, or wrong colour. Usually two or three of them at once, on the same file.

Print Prepper deals with four of those. On the fifth it has an answer you’d want to hear before you sign up. Here’s each one, what the software does with it, and where it stops.

Too small

You upload PDF, Illustrator .ai, TIFF, JPEG or PNG, and you set the DPI you want out the other end.

What happens next depends on what the file is. Photographs can go through Real-ESRGAN. Line art and logos never do. They take a Lanczos resample, because a model rounds off the edges you want kept hard.

The conditions on the photo path are not the ones most people would guess. Real-ESRGAN runs only when the scale factor is 1.2 or more, and only on sources up to two million pixels. So the bigger the customer’s photo, the less likely it is to take the AI path. Real-ESRGAN also only offers 2× and 4×, so whatever factor you asked for gets snapped up to the next one of those. After the resample there’s a sharpening control: off, or unsharp mask at sigma 0.5, 1.0, 1.5 or 2.0.

The photo-or-graphic decision gets made once, on page one’s raster, and then applied to the whole job. It comes out of a thousand-bucket colour histogram with a four per cent threshold, and there’s no model involved in that call. If the check errors, it falls back to treating the file as a photo. A twelve-page PDF with a photo cover and eleven pages of type gets classified off that cover, so a mixed document is the one to watch.

Nothing here guarantees you 300 DPI. You set a target and the tool tells you what it got.

No bleed

Set the bleed in whole millimetres and choose how to fill it. Mirror reflects the artwork outward past the trim on all four edges; Extend carries the edge colours straight outward. Both use the artwork already available.

With Mirror, the pixels along the edge get flipped and repeated into the bleed band. Where the artwork has faces or lettering near the trim, you may see it happen: a reversed half of a face, a line of type reflected back on itself. Extend avoids that reflection but can carry a stray edge colour into a streak. Inspect the bleed in the print PDF before committing to a busy edge; the soft proof shows the trimmed result.

Bleed and crop marks can be switched on or off independently under Advanced print options. Both are on by default. When included, the marks are eight strokes, one pair at each corner of every page, with a fixed style. The PDF records a TrimBox and BleedBox; without bleed, those boxes coincide. With bleed and marks both off, the PDF is trim-sized. There are no registration marks, colour bars or slug information. The page-by-page workflow explains when to use each control.

Wrong shape

Trim comes from a preset or from typed millimetres, plus portrait or landscape. The presets cover A0 through A7, US Letter, Legal and Tabloid, postcards at 4×6, 5×7 and 6×9, the 99×210 DL flyer, business cards at 90×55 and 89×51, square cards and square formats, photo prints, and 18×24 and 24×36 posters.

When the artwork is the wrong proportion for the trim, there’s padding. Padding extends the canvas before the crop, so you have something to frame against instead of cutting into the design.

Two things to know about it. The padding value is a percentage, a whole number from 1 to 100, taken from the current working image’s dimension. It isn’t millimetres and it isn’t bleed. And applying it a second time stacks another bar on top of the first instead of replacing what’s already there. Every step is kept as a revision, so you can step back through ten of them, redo, or restore a version you had abandoned.

Padding is set per page. A multi-page source is split into individual pages on upload, and each page then gets cropped, padded and edited on its own. You can also combine multiple uploads, ordering the files before upload, then rotate or delete individual pages at the crop stage. The remaining pages come back together as one PDF in their job order.

Wrong details

A wrong phone number isn’t a prepress problem, but it lands on the same desk anyway. Print Prepper will edit the artwork itself.

It works one page at a time, and only while the job is at the crop stage. A vision model reads the page and suggests up to four concrete edits it can see are needed: change the phone number to 0400 000 000, remove the second email address under the logo, that sort of thing. You then type a free-text instruction. The only other control is an aspect-ratio hint. There’s no masking, no brush and no region select.

Generation takes roughly 60 to 180 seconds. What comes back is a proposal, and nothing lands on the page until you say so. Your options are Apply, Discard or Refine. The image before the edit is snapshotted, so one click puts it back the way it was.

Because the model picks its own output size, the app measures the returned pixel width against your trim width and reports the DPI you actually ended up with against the DPI you asked for.

Attempts are capped at 200 per organisation per month by default. A generation that fails still counts, since it cost the same call as a good one, but discarding an attempt deletes it and gives you that one back.

Wrong colour

Print Prepper doesn’t fix this one.

The pipeline is RGB end to end, with no ICC profile embedded and no CMYK conversion happening anywhere in it. If a source arrives in CMYK or carries spot colours, the preflight step warns you that the information will be lost, and that warning is the extent of the colour handling.

Conversion stays where it already sits, with your RIP and your press profiles. If that rules the tool out for the work you do, you’re better off finding that out in the first hour rather than at the first proof.

What comes out

Two PDFs. One press-ready multi-page file for the printer, and one low-resolution soft proof to send the client for sign-off, with PROOF across every page so it can’t be mistaken for the press file.

After processing, Imposition can repeat one finished page at actual size on a sheet. It has a separate preview and PDF download and keeps the original outputs available. It does not arrange mixed designs, duplex pairs or booklet pages.

Around that there’s an organisation you invite the rest of the shop into by email, with authenticator-app two-factor. Everyone in it can run jobs; the roles cover who administers the account.