This REST API allows adding watermarks inside the documents.
With this API you can add watermarks with following features:
The watermark could be either a text or an image: Image watermark supports various image formats: PNG, GIF, TIFF, JPG. You may upload the desired image to the Storage and then pass the path as a parameter of Watermark operation; For a Text watermark, you can use various text options like Font, Size, Style, Foreground and Background colors, etc....ScaleFactor Gets or sets a value that defines...Pages to add watermarks to It starts from 1. SpreadsheetOptions...