PressmarksPrepress Tools
Prepress guides

Getting files ready to print, explained.

Short, practical guides to the things that decide whether a file prints clean: bleed, resolution, paper weight, ink limits and colour. Written by people who prep files for press.

Layout · Bleed

What is bleed in printing?

Why every print file needs colour past the trim line — and exactly how much to add.

3 min read
Colour · CMYK

CMYK vs RGB: why your colours change in print

Screens glow in RGB, ink absorbs in CMYK. Why the brightest colours never survive the press.

3 min read
Resolution · DPI

What DPI do you need for printing?

300 is the famous number — but the honest answer depends on size and viewing distance.

3 min read
Paper · Weight

GSM vs lb: paper weight explained

Why '80 lb' means two completely different papers — and how GSM cuts through it.

3 min read
Ink · TAC

What is Total Area Coverage (TAC)?

The hidden ink limit that decides whether your darks dry — or smear all over the next sheet.

3 min read
Layout · Binding

How to calculate book spine width

The formula, the paper-bulk trap, and why your cover template must fit on the first try.

3 min read
Image · Halftone

What is a halftone?

Presses only print solid ink, yet photos look smooth. Dots of varying size are the illusion.

3 min read
Colour · Black

Rich black vs pure black

Why 100% K looks washy on big areas — and why 400% black is a production disaster.

3 min read
Layout · Marks

Crop, registration and bleed marks explained

The little lines around a print file aren't decoration — each one instructs a machine.

3 min read
Paper · Stock

How to choose paper stock

Coated or uncoated, what weight, how opaque — the decisions that change how a job feels.

3 min read
Layout · Dieline

What is a dieline?

The flat blueprint that tells a cutter where to slice, fold and glue a package.

3 min read
Image · Formats

Vector vs raster: which to use for print

Pixels that blur when enlarged, or maths that scales forever — and when each one wins.

3 min read
Colour · Inks

Spot colour vs process colour

Four inks mixed into millions of shades, or one premixed ink that's always exact.

3 min read
Paper · Sizes

Paper sizes explained

Why A4 halves perfectly into A5 — and why US Letter refuses to behave the same way.

3 min read
Press · Dot gain

What is dot gain?

Why your midtones go muddy and shadows fill in once the file hits real paper.

3 min read
Binding · Books

Perfect binding vs saddle stitch

Stapled at the fold or glued into a flat spine — page count usually makes the call.

3 min read
Files · PDF/X

What is PDF/X?

The print-safe PDF standard — and why X-1a and X-4 are not interchangeable.

3 min read
Press · Overprint

Overprint and knockout explained

Whether the colour underneath is cut away or printed through — and why it matters for black.

3 min read
Press · Trapping

What is trapping in printing?

The tiny deliberate overlap that hides the white slivers when plates don't line up.

3 min read
Layout · Book cover

How to set up a book cover for print

Back, spine and front as one flat spread — sized to the millimetre so the fold lands right.

3 min read
Colour · Troubleshooting

Why does my print look different from my screen?

You signed off a bright, punchy file and the proof came back flat. Here's what actually happened.

3 min read
Files · How-to

How to export a print-ready PDF

The handful of settings that turn a normal PDF into one a printer will actually accept.

2 min read
Layout · Business cards

What size should a business card be?

US, EU, UK and Japanese standards — plus the bleed most templates forget to mention.

2 min read
Image · Troubleshooting

Why is my printed text blurry or pixelated?

Fuzzy edges on type or a logo in print? It's almost always one of two things.

2 min read
Files · Checklist

What does a printer need from you?

Tick these off before you hit send, and your job goes straight to press — no emails, no delays.

2 min read