If you are using Adobe layout and graphic design applications like Photoshop, Illustrator, InDesign etc., you are aware that you are offered the chance to save in many different versions of Acrobat when you want to save your work in PDF format.
At this writing, Adobe offers 6 different PDF formats, ranging from Acrobat 4 to Acrobat 9.
As a rule of thumb, it makes sense to save in an earlier version of Acrobat, especially if you’d like the recipient to open and edit your PDF with Acrobat Professional (rather than just viewing it with Acrobat Reader).
But the question lingers: which version is “safe”? That is, which version would maximize the chances of being viewed without compromising the quality of your document, or some of its attributes?
Here is the answer:
Do NOT save in Acrobat 4 format since it does not support TRANSPARENCY.
If your document has any kind of transparency (through blend modes, drop shadows, etc.) then you need to save your document AT LEAST as Acrobat 5. All the newer versions support transparency as well.