NFTs on the most popular blockchain, Ethereum, are simply entries in the smart contract table that handles transactions with this token. Information about the media (metadata) and the media itself for this token, with rare exceptions, are not stored on the blockchain. In this regard, you need to carefully check how reliably the metadata and media are stored in the projects whose NFTs you buy.
At the same time, there is no reason for panic, because the bulk of NFT projects already use fairly reliable methods of storing metadata and media. Therefore, all claims that media can disappear and your NFTs can depreciate in the blink of an eye are mostly groundless.
Among the projects that offer interesting solutions are:
DeekHash is a an promising project. The string is converted into DNA using a hash function, and the DNA determines the character’s appearance. DNA is stored on the blockchain, thus ensuring interoperability and character safety. At the time of this writing, they are available for purchase on the primary market, that is, on the project website.
Pixelchain Art is a very cool project, pixel art that is entirely stored on the blockchain. The color of each pixel is indicated by a symbol, and the resulting string is written to the blockchain. To reconstruct a picture, you just need to read a line and form an image from pixels of the encoded color.
I myself am very interested in how the NFT standards are arranged in other blockchains, especially in FLOW and WAX, and whether the problems that NFT has on the air have been solved there. I will deal with this and keep it up to date.
Now, just a few days before the launch of the NFT platform on ZKSwap, I want to hope that all the achievements of other projects will be skillfully synthesized and implemented. Of course, ZKSwap has a great future and we must support it with all our might.