"Adobe Acrobat Pro is the most commonly used program capable of creating layers from an automated process such as optimization, but even Acrobat Pro does not always produce layers when optimizing a file. The method and settings applied during the saving process play a factor in whether layers will be automatically generated or not. To be clearer on this point, programs like Photoshop and Illustrator will not automatically generate layers when optimizing a file (regardless of the circumstances). Any layered files generated from these programs are reflective merely of layers manufactured by the user.
The metadata for Obama's PDF reveals that a Mac-based program called Preview was used to generate the optimized PDF file.
The bottom line, documented in detail within the report, is that an optimized layer pattern will contain only a single layer of 1-bit quality that displays black only. All remaining layers (in an optimized file) are 8-bit -- containing multiple colors. In other words, the optimization process pulls out all the black color onto one (1-bit) layer -- not two (1-bit) layers, not three (1-bit) layers...just one layer, with this 1-bit object code attribute.
Obama's PDF file (as seen in the figure) contains EIGHT 1-bit layers -- all of which fail to reflect a black color. However, the colors presented are a deception. The black is there, but it's hidden in plain sight (as outlined in the report).
Taking into account the multiple 1-bit layers embedded in Obama's file, combined with the associated color-manipulation defined in the report, it is impossible to duplicate these file attributes through scanning or any other argument thrown at the debate..."
-- Mara Zebest
http://www.americanthinker.com/2012/07/new_obama_birth_certificate_forgery_proof_in_the_layers.html