Originally Posted by
Jaimito Cartero
If it looks professionally done, I doubt there will be problems. If it looks like you've messed with it, then yeah, you're likely to get a lot of extra scrutiny.
I had one extra set of pages added once and it had the wrong passport number written on the note for added pages. No one ever noticed in over 4 years.
Immigration officials got tired of searching for empty spaces, so they stamped over the date/passport numbers on the first added page, not to mention the back flap.
The passport was so thick and unseemly (allegorical representation of the US government?) that not only did the scans stop working early on, but also every now and then an immigration official would give up looking for the entry stamp.