Magic Item Creation

[caseybcrocker]

I'm trying to create a +2 Studded Leather armor magic item. It would have the same ability as the Cloak of Elvenkind with the addition of giving the wearer the ability to turn invisible (per the spell) 1/short rest.

I've got the +2 bonus and the invisibility part figured out, but I cannot figure out how to give the armor the advantage to hide checks like the Clock of Elvenkind does.

Please help!