Seven years back in April 2016 this
thread discussed the problem of adding background color to pdf produced by epub conversion. Back then I advised to try free PDFill tools to add jpeg or bmp texture as all-page watermark to obtain desired background color. My guess is back then in 2016 most people used Windows 8.1 and PDFill tools worked perfectly well for Calibre PDF output.
Today I noticed that under Windows 10 even latest PDFill Editor fails to add watermark as proper background.
OK, I also had latest edition of Adobe Acrobat and decided to find out what was going on. First I verified that both Adobe Acrobat and PDFill Editor were perfectly able to add all-page jpeg texture as watermark to my math pdf books.
However, Calibre generated PDF file opposed to Acrobat/PDFill Editor attempts to add usable all-page background watermark.
See attached screen captures:
First one demonstrates watermark behind page created in PDFill Editor in year 2023 (Adobe Acrobat watermark looks similar).
I intentionally stretched watermark to cover both text and page margins.
Note that watermark is visible ONLY across all four margins but is fully hidden away across the page text.
Second capture demonstrates successful all-page watermark added to Calibre created pdf in year 2015.
Evidently the text area above the 2023 watermark is 100% opaque and hides almost whole watermark.
Also note that Adobe Acrobat simply refuses to change background color for Calibre generated PDF.
My question to Kovid: Is there any hope to return to Calibre generated PDF
its lost since Windows 8 ability to accept proper watermark/background color from third-party PDF editors under Windows 10/11?
P.S. If needed, I have pdf file of Lewis Carrol, Through the Looking Glass created by ePub->pdf in year 2015 – it still allows today to add good all-page watermark under Windows 10