Saving and opening .ozp files in Publish by Zaweba

Saving is the least glamorous part of making a newsletter, and the part you only notice when it goes wrong. Publish by Zaweba keeps its own file type, .ozp, and it is worth knowing a little about what sits inside one, because it explains why your pictures travel with the document and why an interrupted save will not ruin a day's work.

An .ozp file is a ZIP that holds a file called document.json together with the pictures you used. The layout, the text, the styles and the settings live in the JSON part, and the pictures sit beside it. The format is documented in a file called FORMAT.md, so it is not a secret box that only one program can read.

Why the pictures go inside

Many people have opened an old document and found empty boxes where the photos used to be, because the pictures were only linked to files that have since moved. Keeping the pictures inside the .ozp avoids that. You can copy one file to a memory stick, e-mail it to a colleague or move it to another folder, and it opens with everything in place.

The trade off is size. A publication with many large photos makes a large file. If that matters, it is worth sizing your pictures sensibly before you place them, rather than dropping in images straight off a camera.

Atomic, versioned saves

Saves in Publish are atomic. In plain terms, the app does not overwrite your file bit by bit and risk leaving it broken if something interrupts it. The new version is written completely before it takes the place of the old one, so a power cut or a crash during a save leaves you with a good file rather than a damaged one.

Saves are also versioned, which means the file records which version of the format it was written with. That helps the app open older publications correctly as it changes over time.

Publish also repairs slightly wrong files from other tools when it opens them. If a file has been produced by another program and is not quite as the format describes, the app does what it can to read it rather than refusing it outright.

Fonts that travel with the file

Fonts are the other thing that goes missing when a document moves between computers. A newsletter set in a font you installed last month will look different on a machine that has never seen it. Publish lets you embed the fonts in the file as an option. Turn that on when you are passing the .ozp to someone else to edit, or when you are archiving a job you might reopen on a new PC in a year or two.

If the file is only ever going to live on your own machine, embedding is less important, and leaving it off keeps the file smaller. For anything that goes to a print shop, the PDF export embeds the fonts it needs in any case, so this option is about the editable file rather than the finished output.

Opening and getting back to work

The app lists your recent files, so getting back to last week's flyer is a click rather than a hunt through folders. Old Microsoft Publisher files are a separate matter: they come in through the import route rather than being opened directly, and that brings them across as .ozp files you can keep working on.

A few habits make the most of all this. Save early, once the page size is set, so the file has a name and a home. Keep one folder per job, with the .ozp and the exported PDFs side by side. Give files names that say what and when, such as the month of a newsletter, so the recent list makes sense at a glance. And when a job is finished, export the PDF you send out and keep the .ozp as the master you can change next time.

None of this needs an account or an internet connection. Your publications are ordinary files on your own disk, and you can back them up the same way as anything else you care about.