A composite containing an RFID can be mounted on, in, or adjacent a metal object without de-tuning of the antenna of the RFID. The composite includes a first RFID or a EAS device-containing layer, and a foamable material layer held in proximity with the first layer. The foamable material layer expands in size and reduces in density when subjected to external stimuli, such as heat or microwaves. The foamable layer may comprise an intumescent material, and may have RF radiation-absorbing material filler. Pressure sensitive adhesive, when the composite is in a label form, may be used to mount the composite on or adjacent a metal object after printing of the printable surface of the composite, and the foamable material layer is subjected to the external stimuli after printing and either before or after mounting on or adjacent the metal object.