Recently there has been a growing interest around tokens on top of Bitcoin and the Lightning Network. The idea of creating tokens representing assets that can be transferred and stored with the same security and convenience that Bitcoin offers is not new, it was indeed pioneered already in 2013 by protocols such as Counterparty and OmniLayer (formerly Mastercoin), and later adopted by Ethereum and other altcoins, which is also where most of the blockchain tokens activity happens today. However, using altcoins to secure financial assets is not ideal, as they are unable to offer the same level of security and decentralisation of Bitcoin. For this reason, over the years some projects emerged trying to modernise tokens-on-Bitcoin protocols and make them compatible with the Lightning Network, in particular RGB, OmniBolt and, more recently, Taro. This presentation will be focusing on RGB with the goal of providing a comprehensive overview of how it works and what its value proposition is.