Can airport security detect paper inside iPhone?

Don't ask why but I want to sneak a centimeter by centimeter piece of paper onto a plane. I wanted to insert the piece of paper in the SIM card slot. Will a X-ray scanner conveyor belt see paper through the metal of my phone? Will they know paper is in my phone? I'm going to bring the phone onto the plane with me, so it will be with my carry on luggage. Any other tips on how to sneak a centimeter by centimeter piece of paper onto a plane will be appreciated as well!

Man. Its just a paper and small, they don't bother looking at them, x ray won't show the content printed on the paper

They can see inside of your iPone.

They are not interested in a small slip of paper. It will go unnoticed. Would it not be easier to photograph the paper using your iPhone rather than risk losing whatever you wrote on the paper?

Drugs will show. So if you are planning on sneaking LSD inked on paper, do not bother to try. Drugs, fireworks, etc, contain lots of nitrates, and will show up very clearly on digital x-ray.

Cigars in your coat pocket will go unnoticed. Done it many times.

No one cares about a piece of paper. Put it in your pocket.

I can guess what it is. I know someone who just puts it in his shirt pocket. But your way will be OK too.

They may well be able to see it, which could lead to a search to verify what it is. If it's just a piece of paper, then stick it somewhere else in your carry-on bag instead of trying to hide it and look suspicious.