FR4,ceramics,Glass,metalic film, foam, rubber,PCB, fiberglass,wood,PPS,paper and polymers are encasement materials used in RFID tags. Often a specially engineered polyester polymer, a thermoplastic, is used for the final, encapsulating layer of one of the most common tags in use, a polyester tag. Another polymer commonly used is a polycarbonate resin for rugged polycarbonate tags.

Engineered to resist abrasion and very high temperatures, these thermoplastics can ultimately be repurposed when discarded; other materials are more difficult to repurpose such those used in epoxy RFID tags, a thermosetting polymer.

Ceramic tags and FR4 tags are often used when extremely high temperatures are required since they withstand temperatures beyond the range of polymers. Closed cell foam is used as a substrate itself taking the form of the final tag, but it is especially helpful when dealing with tags intended to be in contact with metal.

Used in the interior of some tags, as an isolator,the foam separates the parts of a tag which interfere with one another or the tag with an asset that would be problematic in composition.  In-mold RFID tags seamlessly embed into the asset itself to be both electronically and humanly read even beyond the life of the asset.