How to add a ruler or grid to a PDF view

Rulers and a grid are one menu choice away in PDF by Zaweba: View > Rulers and grid. Millimetre rulers appear along the edges of the view and a grid is drawn over the page, with its spacing set in Preferences > Page display and a Snap to grid option. Guides can be dragged out from the rulers, or made with View > New guide.

They are viewing aids. They help you judge position and alignment on the page, and they don't change the PDF itself, so you can switch them on and off as often as you like.

When rulers and a grid help

Checking a layout is the obvious case. If a flyer, a form or a sign is meant to have margins of a set width, the rulers show at a glance whether it does. A grid makes it easy to see when columns or boxes don't quite line up.

They are also useful when you're adding things to a page yourself. Placing a text box, a stamp or a comment so that it sits square with the existing content is far easier with a grid behind it, and with Snap to grid turned on, what you place lands on the grid lines rather than a hair off.

For drawings, rulers give a quick sense of size and position, though for real measurement the app has separate measuring tools.

Turning them on and adding guides

Open the document and choose View > Rulers and grid. The rulers appear at the top and side of the view, marked in millimetres, and the grid is drawn over the pages.

To change the spacing of the grid, go to Edit > Preferences and open the Page display section. A fine grid suits detailed work; a coarse one is less distracting when you only want a rough guide. Turn on Snap to grid there if you want placed items to jump to the lines.

To add a guide, drag from a ruler onto the page, and a line follows your pointer until you let go. Or choose View > New guide. Guides are good for marking a single line you care about, such as a margin or the top of a column, without the clutter of a full grid.

Grid spacing and snapping

Match the grid to the job. If you are checking a design built on 5 millimetre steps, set the grid to 5 and the misalignments will jump out.

Use guides for the few lines that matter and the grid for general alignment. Too many guides and the page gets hard to read.

Remember snapping when it isn't wanted. If something won't sit where you put it, Snap to grid is probably pulling it to the nearest line; turn it off for that move.

Inches or millimetres

The rulers are in millimetres. Elsewhere in the app, Edit > Preferences has a Units section that can be set to millimetres, centimetres, inches or points, which governs how sizes are given to you in other places. If you think in inches, it's worth setting that early.

Proofing a design

Rulers, grid and guides sit alongside the app's other display tools in the View menu: page layouts, rotate view, full screen and layers. Together they make PDF by Zaweba a good place to proof a design before it goes to print, and since the app runs offline, files from clients stay on your own PC while you check them.

Turn them on, check what you need, and turn them off again. They're there when the page needs a closer look.