What does flattening of a PDF mean for printing?
I have created a PDF with images in it. The images are on different layers in PDF. PDF also contains some layers which have some text on it. The images are of the required resolution (>300 DPI) for printing. Also, some layers have transparency in it (want to make the background layer visible).
But when I send that PDF to a print office, it says flatten the PDF and remove transparency. I have the following questions about flattening the PDF:
- What does flattening the PDF mean? (I suppose make it a single layer document)
- After flattening the PDF, would I loose the resolutions of the images and what would the final resolution be?
- Will the PDF be transparency free after flattening?
- What are the things that I will loose after flattening the PDF (what are the limitations of the flattened PDF)?
- How to flatten a PDF?

I have tried to find the answers of these questions by myself, but I think I need some PDF expert for these questions. Please help me out.
Thanks in advance.
