PDF print optimizer

How the optimizer works

1. Choose your PDF. Up to 12 pages, spread evenly through the document, are measured at a small size.
2. Read the findings. Each one says what was measured and whether it needs attention, is slight, or is fine.
3. Apply the recommended settings, or adjust the sliders, the print colour and the page handling yourself.
4. Compare the original with the result, then download the new PDF. Every page is processed when you apply, not only the measured ones.

What it measures, and what it does not

The findings come from numbers measured on your pages, not from guesses:

• Ink level — how dark the darkest marks are, from 0 (black) to 255 (white).
• Paper level — how white the background is.
• Contrast — the gap between ink and paper.
• Lighting — whether the paper level varies across the page, which is what a shadow or gradient looks like.
• Colour — how much of the page carries colour, which matters if you print in mono.
• Page type — whether a page is text and vector graphics, or contains images and will be re-rendered as an image.
• It does not measure speckle or noise, blur, the resolution of embedded images, or how your printer behaves. If you can see speckle, raise Noise reduction; if the scan is soft, sharpening helps a little but cannot restore detail that was never captured.

How to make a PDF darker for printing

There are two places a faint print can come from, and the order matters. Fix the file first, because that change is permanent and travels with the document. Then check the printer, because a toner-save mode will lighten even a perfect file.

• Let the optimizer measure the file. If the ink or paper findings say "needs attention", the file is part of the problem.
• Raise Text darkness until the ink is solid, and Background until grey paper turns white. The recommendation sets both from your measurements.
• Leave Thicken thin text on for text pages: a very thin font can be pure black on screen and still print faint.
• Print a single page first and look at the smallest text and at any stamp or signature.
• If every document prints faint, turn off toner-save or draft mode and check the cartridge. See PDF prints too light, darken a PDF for printing, and the guide on making a PDF darker for printing.

Grayscale or black and white?

Both remove colour. They are not the same.

• **Grayscale** keeps every shade of grey. It suits a mono printer and anything with shading, photographs or signatures.
• **Black & white** forces every pixel to pure black or pure white. Edges are crisp, but all mid-tones are lost, so it is only suitable for plain text and line art.
• If colour carries meaning, such as a legend, a highlighted row or a status column, check the grey result before printing many copies: different colours can land on very similar greys.

Why pages can be adapted separately

A document often mixes pages: one clean digital page, one faint scan, one with a shadow. A single set of numbers would over-correct the good page or under-correct the bad one. With Adapt each page separately on, every page is measured on its own and its sliders are chosen for it. The optimizer turns this on by default when the sampled pages differ a lot.

Limits

• Pages that contain images are rendered as images, at 200 DPI. Pages made only of text and vector graphics keep their real text.
• It is built for office and home printing. For press work with spot colours, ICC-managed CMYK or bleed, talk to the printer first.
• Scanned pages are not given a searchable text layer.