Adding watermark results in unexpected and unreasonable increase in file size.
I have a 54 page architectural drawing set which I created by printing directly from my CAD application to Acrobat. Each time this drawing set is provided to a third party, I need to add a watermark with a date and title which uniquely identifies the drawing set based on who it was provided to and why. Each page has a title block with a space designated for this watermark. Prior to adding the watermark I spent much time experimenting, testing and optimizing the sequence, settings and processes for creating this document set and I finally feel like I have maximized document quality and file size. Unfortunately, once I add the watermark, the file size is unreasonably increased.
1. The watermark I am adding contains three lines and 46 characters of text using an 8 point font. Prior to adding the watermark, the file size is 5,376 KB. Adding the watermark increases the file size to 6,434 KB, an over 1MB increase! Auditing space usage shows that the increase in contained almost entirely in content streams. The embedded font increase was less than 4KB. Investigating further, I decided to try and add a watermark by typing directly into the text box in the watermark dialog instead of adding from an outside file. To my surprise, this increased the file size to 6,885 KB which is an even bigger increase than adding my own watermark. Still scratching my head, using the same add text from the watermark dialog, I changed the text to a single period. The file size was still increased to 6,872 KB. A 1.5MB increase for a single period!!!
Testing further, I decided to print a 54 page document with only my title block and no other drawings or data. I printed this using the exact same process from the same CAD application as the original drawing set above. The resultant document prior to adding the watermark was 199 KB. Adding my original watermark to all 54 pages of this document increased to file size to 211 KB or a 12 KB increase.
So, to summarize, if I add the watermark to a 54 page document with little content, the file size is increased by 12 KB. If I add the same watermark to a 54 page document with more content, the watermark increases the file size by more than 1 MB!
What the @##$%% is going on!? Every time I think I have Acrobat figured out, it throws me another curve ball.
