That's completely implausible. There's no way someone can photoshop an embossed marking. The creases (that he claims are way too thick) go right through the embossing. Take a look here: http://www.factcheck.org/UploadedFiles/birth_certificate_5.jpg and tell me if you honestly think that the embossing was photoshopped onto the final picture.
The only possibility of forgery would come from someone obtaining the embossing tool plus the notary rubber stamp and using them on a printout of a forgery. The forgery would also require either printing on the same hashed paper or a laser printout of the hashes.
I’m bemused by your insisting that something can’t be done, invariably followed by how to do it.
Please do not quote factcheck data to me. I saw their pathetic attempt to mislead when it was first posted on their website and noticed that neither the front or the back of the document is clearly shown in any one image, the one that comes closest to a full image of the front is deliberately obscured by the shadow of an arm. They must think we are idiots.
Factcheck.org is an unreliable source. It is part of the Annenburg group and an ACORN organization started by Obama.