Some photos in the book may have transparency.
Did you receive a pop-up when uploading your book notifying you that one or more of your images may have transparency? This means that you might have placed either a PNG or TIFF file in your project. Note that any transparent parts of the image will be filled with white when rendered.
You can test any affected pages by exporting your book to PDF by going to Book Settings in the upper right corner, selecting Book>PDF and then clicking Export book to PDF in the bottom right corner. Review the exported PDF to look for any problems.
To fix an image that has been flattened with white:
- Go to the source image.
- Flatten and re-save it, or save as a JPG (which will automatically flatten the content).
- Re-import any flattened JPG files into Lightroom, then into your book.
If your image looks fine in the exported PDF but you're still getting the transparency warning, use the "Send Book to Blurb" button to upload the book. Then, before ordering, use the online preview available for your book on the My Projects page. If your photos look fine there then the printed book should look fine as well.