Abstract: A release coated liner and security labels containing such release coated liners are described. In one embodiment the labels comprise(A) a sheet having an upper and a lower surface;(B) an adhesive layer having an upper surface and a lower surface and having its upper surface in contact with the lower surface of the sheet; and(C) a liner with a release coating removably affixed to the lower surface of the adhesive layer (B) wherein the release coating contains a microencapsulated material which is capable of marking a substrate when (a) at least some of the capsules are broken, (b) the liner with release coating is removed from the label, and (c) the label, without liner and release coating is applied to a substrate.The sheet (A) may be a multilayer sheet. In preferred embodiments, the microencapsulated material is an etchant or a fluorescent agent. The security labels may be applied to glass or metal and is preferably applied to painted glass or metal.