Every writer has a story about lost work: the laptop that died, the file that was overwritten, the cloud sync that quietly replaced a chapter with an older version. The advice is always the same ("back up your work"), and it is rarely specific. This guide is specific. It explains the 3-2-1 rule, where Quillen keeps your books on your computer, how to copy them safely, what a cloud sync folder protects you from and what it does not, how to keep extra exports as a second line of defence, and how to test a backup so you know it works. Quillen is local-first, which means your manuscript lives in ordinary files on your own computer: that gives you full control, and it also makes the backups your job.
The short answer
Keep at least three copies of your work, on two kinds of storage, with one copy somewhere else. Quillen stores each book as a folder in a folder named Kaiyo Author inside your Documents folder, so backing up means copying that folder. Do it on a schedule, close Quillen first if you can, and check that a copy opens. Export a Word or PDF copy of finished chapters as an extra safety net.
The 3-2-1 rule
| Part | Meaning | Example |
|---|---|---|
| 3 copies | Your working copy plus two backups | Your computer, a USB drive, a cloud copy |
| 2 kinds of storage | Different media, so one failure cannot take both | Internal drive and an external drive |
| 1 copy elsewhere | Off-site, in case of fire, theft or flood | A cloud service, or a drive kept at a friend's house |
A single backup on the same drive as your work is not a backup. If the drive fails, both are lost. And a synced folder is not a backup by itself, because a deletion or an overwrite syncs too.
Where Quillen keeps your books
Quillen saves everything as files on your computer. Books live in a folder called Kaiyo Author inside your Documents folder. Inside it:
- One folder per book, named after the book with the ending .kaiyoproj. In our test, changing a book's title did not rename its folder, so the folder name can differ from the title you see in the app.
- Shared items beside the books: folders for notes and to-dos, a file for your personal dictionary and a file that records the order of the books on your bookshelf, plus a folder for series information.
- Covers, maps and images are stored with the book that uses them.
On Windows the Documents folder is usually in your user folder, and if you use OneDrive it may live inside OneDrive. If you are not sure where yours is, open Documents in your file manager and look for Kaiyo Author. Because the structure can change between versions, treat this as a description of the current layout, and back up the whole folder rather than picking individual files.
How to back up the folder
- Close Quillen, or at least leave the book you are working on and return to the home screen, so that nothing is mid-save.
- Find the Kaiyo Author folder in your Documents folder.
- Copy the whole folder to your backup location: an external drive, or another computer.
- Add the date to the copy's name, such as Kaiyo Author 2026-11-08, so you can keep several versions.
- Keep more than one version. A backup made after you accidentally deleted a chapter is no help. Keep a few older ones too.
Cloud sync: helpful, not enough
Syncing the folder with a cloud service gives you an off-site copy with no effort, which is good. But sync is not versioned backup. If you delete a scene, the deletion syncs. If two computers edit at once, one may overwrite the other. If a file is corrupted, the corrupted file syncs. Some services keep file history for a limited time, which helps, but check how long. A good setup uses sync for convenience and off-site safety, plus a separate, dated backup that does not sync.
One practical caution: if your Documents folder is synced, avoid opening the same book on two computers at the same time, and let a sync finish before you open the book on another machine.
Exports as a second line of defence
Your manuscript is safest if it exists in a second, independent form. After finishing a chapter or a draft, export a Word copy. Quillen can export a manuscript as Word or PDF, which anyone can open without Quillen, so it protects you even if the app or its files are unavailable. Name the files with the date and keep them with your other backups. See how to prepare a submission package for the Word export.
Test your backup
A backup you have never opened is a hope, not a backup. Once in a while, copy the backup somewhere else, open it and check that your latest chapters are there. If you can, open the book in Quillen from a restored copy. Do this before you need it.
A simple routine
| When | What |
|---|---|
| After every writing session | Let the app save; nothing else needed |
| End of each day | Make sure cloud sync has finished, if you use it |
| Weekly | Copy the Kaiyo Author folder to an external drive, dated |
| After finishing a chapter or draft | Export a Word copy and store it with the backups |
| Monthly | Open a backup copy to check it works; delete very old ones you no longer need |
| Before moving to a new computer or upgrading | Make a fresh backup first |
Common mistakes
| Mistake | Problem | Fix |
|---|---|---|
| One copy only | A single failure loses everything | Follow the 3-2-1 rule |
| Backup on the same drive | Fails along with the original | Use a different device |
| Relying on sync alone | Deletions and overwrites sync too | Keep dated copies that do not sync |
| Overwriting the last backup | No older versions | Keep dated copies |
| Never testing a backup | It may not work when needed | Open one regularly |
| Copying single files from a book folder | A partial, inconsistent copy | Copy the whole folder |
Do it in Quillen
Quillen does not run backups for you: its files are ordinary files on your computer, so you use your own tools. What it gives you is the ability to export independent copies.
- Know where your books are. They are in the Kaiyo Author folder inside your Documents folder, one .kaiyoproj folder per book.
- Back up the folder on a schedule, with the 3-2-1 rule, as described above.
- Export Word copies. Open your book, click Export, choose Agents & publishers or Print, eBook & Kindle, pick Word (.docx) and export. Keep the file with your backups.
- Keep your cover files. Use Save project in the cover editor to keep a cover project file, and store it with the book's backup.
- Test a restore by copying a backup of one book to a new location and checking that its text is all there.
Checklist
- Three copies, on two kinds of storage, one off-site.
- The whole Kaiyo Author folder copied, with the date in the name.
- Several older versions kept.
- Word exports of finished chapters stored separately.
- Cloud sync finished before opening a book on another machine.
- A backup opened and checked regularly.
Common questions
Where does Quillen store my books?
In a folder named Kaiyo Author inside your Documents folder, with one folder per book ending in .kaiyoproj, plus shared files for notes, to-dos, your dictionary and bookshelf order.
How do I back up my Quillen books?
Close Quillen, copy the whole Kaiyo Author folder to an external drive or another computer, and put the date in the copy's name. Keep several dated versions.
Is cloud sync enough for backup?
No. Deletions and overwrites sync too. Use sync for convenience and off-site safety, plus separate dated backups that do not sync.
What is the 3-2-1 rule?
Keep three copies of your work, on two kinds of storage, with one copy off-site.
Does Quillen back up automatically?
No. Its files are ordinary files on your computer, so you back them up with your own tools. Word exports give you an independent second copy.