Format notes

FastImpose reads PDF and writes PDF. In between, it does one thing: it places your pages onto sheets. This page sets out exactly what that means, and — at least as importantly — what it does not.

How pages are carried through

Each source page becomes a vector form XObject and is placed on the sheet with a transform. That is the whole mechanism, and it has consequences worth stating individually:

• Nothing is rasterised. No page is rendered to pixels at any point. Scaling to 65% or 300% is a change to a transformation matrix, not a resample.
• Text stays text. Fonts, glyphs and encodings come through as they were. Text in the imposed file is still selectable and still searchable.
• Vectors stay vectors. Curves are curves at any scale. There is no resolution at which a logo becomes soft, because there is no resolution.
• Images come through as they are. Their sampling and compression are untouched — an image placed at 65% is the same image data, transformed.
• Colour comes through as it is. Whatever colour space your page used, the imposed page uses. Nothing is mapped, converted or normalised.

The imposed file is a new document, laid out on the sheets you specified, containing your pages unaltered.

What is not done

Imposition software often sits inside a larger prepress suite and inherits a long list of neighbouring capabilities. FastImpose does not have them. Stated plainly, so that nobody discovers this at the wrong moment:

• No colour conversion. Nothing is converted between RGB, CMYK, greyscale or spot. Not on import, not on export, not silently in between.
• No ICC profile handling. No profiles are applied, embedded, substituted or honoured. There is no output intent.
• No PDF/X conformance checking. The output is not validated against PDF/X-1a, X-3, X-4 or any other conformance level, and no claim of conformance is made.
• No preflight. Nothing checks your fonts, your image resolution, your overprint settings or your transparency.
• No ink coverage or TAC calculation. No total area coverage figure, no ink limit warning.
• Creep needs a job-specific setting. Set the creep amount and direction in Booklet; paper weight does not calculate the allowance automatically. See Booklet imposition for what that means in practice.
• No marks beyond crop marks. No registration marks, fold marks, collation marks or colour bars. See crop marks.

Why the line is drawn there

An imposer that quietly converts colour is how a proof stops matching the press.

That is not a rhetorical flourish; it is the specific failure the omission is designed to prevent. A colour conversion applied without being asked for is invisible in the file, invisible on screen, and visible on the sheet — usually as a black that has gone four-colour, a spot that has become a process build, or an image whose neutrals have shifted. It is found late, it is expensive, and it is very hard to trace back, because the operator's mental model of the file no longer matches the file.

Colour management is a workflow-level responsibility. It belongs where the profiles are known, where the press condition is known, and where somebody is accountable for the result — in the RIP, or in the application that produced the artwork. A tool whose job is to arrange pages on a sheet is the wrong place for it, and doing it badly is worse than not doing it.

The same reasoning covers the rest of the list. Preflight that misses things is worse than no preflight, because it manufactures confidence. A PDF/X claim that has not been properly validated is worse than no claim. A colour bar printed by software that does not manage colour is a decoration pretending to be an instrument. In each case the choice is between an honest gap and a dishonest feature.

Fitting it into a workflow

The practical arrangement is straightforward, and it is what most short-run shops are already doing:

1. Produce and correct the artwork in the layout application, with its colour settings and its export presets.
2. Preflight there, or in a dedicated preflight tool, before imposition. Fix problems at the source, where the artwork is editable.
3. Impose with FastImpose. Nothing changes except position.
4. Let the RIP handle colour for the press condition it is driving, which is the only place that knows what that condition is.

Impose last, and the imposition never has an opinion about your colour. That is the intended shape.