NOTE: ON1 PHOTO RAW 2019 and 2020 sidecar files are enabled by default.
Photo RAW has the ability to save your non-destructive edits either to its database, or to .ON1 sidecar files. Once enabled, the sidecar files will be generated automatically and stored alongside the image they belong to with the same name, and in the same location. If you have edited images previously with sidecars disabled, your non-destructive changes will be migrated to a new sidecar file for your images once they are opened in Develop or Effects, or if you modify their metadata.
Once enabled, you'll see files such as the .ON1 file below appear next to your images within your file explorer. These files will share the same name as the image they belong to, but do not replace your original image. Note, these files will not be visible within Photo RAW itself.
First, open Photo RAW's Preferences menu by clicking the ON1 Photo RAW 2017/2018 menu > Preferences in the Mac version, or the Edit menu > Preferences in Windows.
Select the Files tab, then check the box next to 'Save ON1 sidecar files for non-destructive edits and metadata'. Click OK after you've checked this box.
Enabling sidecars is recommended for both backing up your non-destructive edits without exporting your images, and for sharing images across multiple computers or installations of Photo RAW. To backup or share your non-destructive edits, make sure to move both your original file and its sidecar to the same destination. To easily access both your image and sidecar through Photo RAW, select the image in Browse, then right click and select "Show in Finder/Explorer" depending on your operating system.