Checking crop, trim, bleed and art boxes in PDF by Zaweba

Every PDF page has a size, but a print-ready PDF usually has several. It carries a set of boxes that tell printers and programs where the page is cut, how far the artwork runs past the cut, and which part counts as the design. These boxes are invisible in normal viewing. PDF by Zaweba can draw them on the page so you can see them for yourself.

The four boxes

The crop box is the area a viewer shows on screen and most programs print. The trim box is the finished size of the page after it has been cut, for a business card or a flyer the size it ends up in your hand. The bleed box is a little larger than the trim box. It marks how far colour and pictures that run off the edge extend past the cut line, so that a slight wobble in the guillotine doesn't leave a white sliver. The art box marks the meaningful content of the page, the part a designer intends to be placed when the page is used inside another layout.

Not every PDF sets all of them. A document saved from an office program often has only one page size, in which case the boxes all match and there is little to see. Files exported for professional printing are the ones where the differences matter.

Showing them

Choose View > Show page boxes. The app draws the page's crop, trim, bleed and art boxes on the page, each as its own outline, so you can see how they relate to the artwork and to each other.

What to look for

Bleed is the most common thing to check. If a picture or a coloured background is meant to run off the edge of the finished page, it should reach past the trim box out to the bleed box. If the colour stops exactly at the trim line, any tiny shift in cutting can leave a white edge. Seeing the boxes drawn makes this obvious at a glance.

Look at the trim box against the important content too. Text and logos too close to the trim line are at risk of being cut or looking cramped. Printers usually ask for a safe margin inside the trim, and with the trim box drawn you can judge whether the design leaves one.

Check that the trim box is the size you ordered. A flyer meant to be A5 should have an A5 trim box. If it doesn't, the file may have been exported at the wrong size, and it is far better to find that out before it reaches the printer.

Using it with other tools

Page boxes work well alongside the rulers and grid in PDF by Zaweba. Turn on the millimetre rulers to measure how much bleed there is or how wide the safe margin is. Zoom in with the zoom tool on corners where artwork meets the edge.

They are also useful the other way round, when you receive printed work as a PDF proof. Showing the boxes confirms what the printer is going to cut, and helps you spot a mismatch between what you approved and what they set up.

Who needs it

Anyone who sends files to print, from small businesses ordering leaflets to designers and print buyers, will find page boxes worth checking. It takes a few seconds to turn them on, and it can save a reprint. For everyday reading they are simply something to leave switched off, and PDF by Zaweba keeps them out of the way until you ask for them.