Holomarks500 Security Seal .59 x .59 Inch, Void Hologram Stickers, Warranty Tamper evident Holographic Labels .59 x .59 Inch

I am using these to tag company-issued phones. If you clean the plastic surface with rubbing alcohol first, these stickers stay put and can't be removed without revealing the VOID message. One thing to note is that the text is printed on the label, not etched into it, so with enough time, or with enough rubbing, the text will come off. I was able to remove the printing with about 30 seconds of hard rubbing with a pencil eraser.

They require going over the sticker a few times before it sticks

kind of small

They work great. Very sticky to the paper I'm using them on. Upon removal the security does its job and leaves a matrix grid.