Admins can enable a "Draft" watermark to display on a previewed Quote Document as long as the Quote is in the "Draft" stage.
Watermark ID: The value of this Quote Template field should contain the Salesforce ID for the document containing the watermark image used in the Quote PDF.
Watermark Shown: Select this Quote field to have all previewed Quotes in Draft status display your selected "Draft" watermark.
Admins can ensure a previewed/printed Quote in Draft status is labeled accordingly so it is not accidentally confused with a finalized Quote.
Admins may need to modify the following page layouts:
Linking a watermark to the draft status:
You can create a workflow rule to control when a watermark appears on your quote output. This will ensure only non-finalized quotes are watermarked. This Workflow Rule should apply to the Quote Document object.