Getting started with NFC can be overwhelming at first. Jargon like NFC Forum, Tag Type 1,2,3,4, NDEF, NFC chip, NTAG203, Ultralight, DESFire and Mifare can be confusing, not to mention the different shapes and sizes of NFC tags available. The thing is, choosing NFC tag is not as hard as it seems to be. First you need to get an NFC reader obviously. This can be either an NFC enabled mobile device or a PC connected NFC reader. A reader is a general term, you can be assured that they can write as well :).
Next, you need to get some NFC tags and the first step is to choose which NFC chip to use. NFC chip or IC (Integrated Circuit) is the heart of every NFC tag. NFC chips differs in technical characteristics such as memory layout as well as security features that they can support. The major factor when choosing NFC chip is the amount of memory it can hold. Think about what do you plan to store in the tag. If you plan to store a short URL or short text, an Ultralight tag with 46 bytes is sufficient. NTAG203 tag with 137 bytes of memory is good enough for almost all purposes. The have excellent scan performance too. If you plan to store big amount of data such as vCard (contact data), you might want to choose Mifare 1K or DESFire EV1 4k/8k. In general, NFC tag with bigger memory space tends to cost more and the response time tend to be slightly slower.
Another factor to consider when choosing NFC chip is the NFC Forum Type Tag standard compliance. It is a standard to ensure interoperability between NFC tags and NFC devices. There are 4 types of tag (Type 1,2,3 and 4) defined in the standard. Type 2 and 4 tags are mostly common in our store. Mifare 1K chip is not adhering to standards by NFC Forum. Some devices are known to have problem to work with it. Based on our findings, Blackberry, Windows Phone and some of the newer Android devices such as Nexus 4 and Nexus 10 have problem with Mifare 1K. Nevertheless, this chip is commercially available for quite some time and widely used in many areas. If you know that your device can read Mifare 1K and do not plan to share your tags publicly, it is OK to use Mifare 1K. It has decent amount of memory (about 5 times bigger than Type 2 tag) and relatively cheaper. Just bear in mind that your future NFC devices might not be able to read it. If you plan to place your tag in public area, it might be good idea to avoid this chip.
The next factors are shapes and sizes of your NFC tags. You have to consider where the tag will be placed and the environmental condition surrounding it. Stickers or labels are the most popular form of NFC tags. Once stuck, they are seldom removed. They are a good choice for smart posters and task automation on your phone. Paper based stickers cannot withstand harsh outdoor condition. Stickers made from film or PVC fare better. Normal NFC tag would not work on metal surfaces or on electronic devices as they interfere with the signal. For this, you need an on-metal NFC tag. It has an additional ferrite layer, shielding the tag from electromagnetic interference. Due to this extra layer, on-metal stickers are slightly thicker than normal stickers.
Products like key chains and cards are useful if you want to carry a NFC tag along with you. They are portable and slip easily in your pocket or wallet. They are made out of PVC, so they are more durable and have better water resistance than the stickers.
When choosing tag sizes, you want to make sure that there is enough room to put your tag. NFC stickers should stick flat and firmly on a surface. It is not advisable to bend or fold them as the antenna might be damaged. In general, bigger tag gives better scan performance. However, if you like your tag to be hidden and inconspicuous, choose the smaller tag.
Finally, get an application or software to encode your NFC tags. For mobile phones/tablets, there are plenty of applications available that can read and write your tags. Some applications will tell you how big is the data that you want to encode so that you know which NFC chip to use.
There you go, a short guide on how to choose your NFC tag. Happy tapping!