RFID inlays are composed of an IC (Integrated Circuit, Chip) and a Dipole antenna. To attach the antenna to the IC we commonly use a strap.
RFID inlays can be either "wet" or "dry"
Antennas can be made of silver, aluminum or copper, with each material producing very specific read and write characteristics because of the different chemical properties. While there are some more exotic materials sometimes used for antennas they are considerably more expensive to produce and very vertical application specific. Generally a copper antenna is slightly more expensive that aluminum or silver but is more conductive and usually provides a longer distance read capability.
Inlays come on rolls ready to package/ecapsulate into finished tags. Each roll contains between 5,000 and 20,000 inlays and the automated equipment to make a tag must be set up for each roll type so a production run of 5,000 tags can easily be a single roll or a 1/4 of a roll. Most converters operate JIT facilities meaning that stock or inventory is not kept since there are so many varieties of inlays that can be used to produce a single tag.
Just as there is a very wide variety of IC's for inlays, there is also a very wide variety of antennas ranging from very small - Dot, Button, Paperclips through DogBone, Hammer, Crab, Radar, Satillite, Squiggle, Mini Squiggle, Torpedo, Xcaliber, Web and Frog sizes - each inlay usually has a specific name to identify it.
Size and shape of the antenna determines the read and write distance and speed characteristics.
The small sample below depicts actual HF and UHF inlays at approximately 1/2 their actual size. Gen 2 inlays range in size from 7mm dia - 0.276 inches(Microdot) through 76.2 x 76.2 - 3 inches by 3 inches (Frog), to antenna designs that are aver 150 mm - almost 6 inches long.
Most inlays are designed for a specific application use - a single inlay can not and will not work for multiple types of RFID requirements. Inlays that work near or on metal do not work as well on wood or plastic.
We do not expect you to be the experts on inlays, IC's and packing for the final tag that will work for you as it would be a fulltime job. To obtain more information on what tag your specific application requires