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Minting Multi-File NFTs on Hedera Using HIP-412 Standards

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This article was originally published May 24, 2022 on the official Hedera blog.

Art is a force that evolves our culture and drives the adoption of new technologies. Limitations often inspire creativity; ultimately forcing us to expand our horizons and deepen our connection with each other. Tokenizing artwork on a DLT has unlocked a whole new realm for artists where value can move freely, utility is unleashed, and the real world can converge with the virtual one. It’s all quite magical.

Countless creators are choosing Hedera as the place to build their projects, including ourselves at Doerksen & Davenport Inc. Minting carbon negative, sustainable NFTs with low fixed fees right on the native layer speaks to the core values of artists, musicians, filmmakers, and 3D model designers. There are so many exciting goodies this ledger offers like Smart Contracts 2.0, but there’s something specific we want to focus on regarding NFT “metadata”, more specifically “JSON schema” and how a new set of official standards called “HIP-412” just changed the game for everyone

A new challenge

Metadata is the DNA of every NFT. It tells wallets, apps, launchpads, and marketplaces what’s inside your NFT, where it is, and what to do with it. If our metadata isn’t up to standard, it can become very hard for the ecosystem to evolve and support our NFTs. However, when we all get on the same page as a community, teach each other and follow guidelines, we can supercharge what’s possible with tokenization on web3! Let’s discuss how we used the new HIP-412 metadata standards to create multi-file NFTs for PixelRug 3D collectibles and the beloved HBAR anthem Hashanty.

As most artists know, inspiration can strike when you least expect it. The idea for the Hashanty was sparked during a morning commute, as a fun-lighthearted song for the Hbar community, and quickly became an educational tool that described the culture and story around Hedera in a way that newcomers could understand. In a similar fashion, the concept of a 3D PixelRug bubbled up before falling asleep after a day of wandering around metaverse NFT art galleries, looking at all the empty virtual floor space. Although the artistic mediums are different, both projects were presented with the same challenge: they weren’t an image file.

The “image” problem

//Shoving a round peg through a square hole. That poor image field…
 "name": "Hashanty (Limited Edition)",
 "creator": "Joshua Lucas",
 "description": "A fun song about Hedera Hashgraph!",
 "image": "ipfs://bafkreihpqwdnf..." // An audio file, yikes!

A big roadblock for NFT metadata is the “image” field, seen in the JSON schema example above. For a long time, creators were forced to use this image field for files that weren’t images, and this made the process quite messy. There were some inventive workarounds, but without official standards, the experience for collectors was lackluster and it was tricky for wallets and marketplaces to juggle all sorts of varying schema. The challenge was to figure out a way to support many different types of files that artists would need and offer multi-file support. These official NFT standards needed to be created with all types of artists in mind.

We were part of a group assembled by May Chan of HashPack to propose HIP-412, a set of standards for NFT token metadata JSON schema, and we were so excited to see the HIP accepted by Hedera. With these new standards, the limitations disappeared for our NFT projects and we were able to focus on creating a bundled package to enhance the collector experience. With our artwork ready, it was time to mint our NFTs to the Hashgraph and take full advantage of multi-file support.

Creating multi-file NFTs

Below is an example of how we applied HIP-412 JSON schema to create some of the first multi-file NFTs on Hedera. With these new standards, the “image” field gets a much-needed break and our different types of files are handled properly in an array. For Hashanty, we were able to include a lyric sheet and video file alongside the music. For PixelRug, we were able to include the 2D artwork and a collectible poster bundled with the 3D model.

//It’s important to note that information such as “supply”, “royalties” and other properties which are recorded on ledger should not be defined in the metadata (they don’t need to be).

 "name": "Purple Punk (Limited Edition)",
 "creator": "PixelRug",
 "description": "A quirky 3D metaverse collectable.",
 "image": "ipfs://bafkreihmarfptui7ai34gzmb6y...", // A thumbnail JPG
 "type": "image/jpeg",
 "files": [
     "uri": "ipfs://bafkreie7c4nzsqxg32qevaxzv...", // A GLB 3D model
     "type": "model/gltf-binary"
     "uri": "ipfs://bafkreieui6jn5wbnw6i2oyh2a...", // A PNG image
     "type": "image/png"

So what was our process? First, we organized all of the information we would need for our NFTs like the name, creator, and description. Next, we uploaded all of our files to IPFS, the gold standard in decentralized, long-term storage using a tool called NFT.Storage (you don't want to host your files on a traditional web server like AWS, your collectors want them to be around forever)! Finally, we used a tool created by community member Matt Woodward of Affirmation NFT to run some tests on the Hedera testnet and when things looked good, we did a final mint of our new NFTs. When you mint on Hedera, initially an account is created that has properties like “supply” and “royalties” and then each of your tokens are minted inside that account in a serialized fashion. Depending on how the account is set up, you can mint more tokens and do all sorts of things later on.

But what about that “image” field? Well, it’s not really required anymore, but it can also be more useful than ever before! A problem with NFTs that contain more demanding file types like videos and 3D models is that they take a lot of resources to display inside a wallet or marketplace (especially when you have a bunch of them). Now, the image field works like a thumbnail; the cover artwork for your wonderful multi-file NFT allows these more advanced files to be revealed once inside the NFT. What’s even cooler is that multi-file NFTs on Hedera doesn't require a smart contract and they have all the benefits of every other HTS token.

Get “hip” to a multi-file future

So what do multi-file minting and HIP-412 standards mean for the future of NFTs on Hedera and beyond? The world of tokenized artwork is still in its infancy; having started with JPEGs, the ecosystem is hungry for more. The broader art world outside of DLTs offers all kinds of physical and digital experiences that activate and engage all our senses, not just visual. HIP-412 now sets the stage for the NFT ecosystem to mirror the art world outside of crypto and invite a more diverse ocean of artists to express themselves by standardizing and expanding the DNA of our non-fungible creations. What makes Hedera NFTs special is it’s all just metadata. The rest is all handled by the token service. This truly is an art renaissance of the digital and information eras.

Screen Shot 2022 05 24 at 1 51 28 PM
A screenshot of what a multi-file HIP-412 NFT looks like inside HashPack Wallet.

At our creative agency, we’ve worked with a lot of incredible artists that have no experience with crypto. Many of them are wanting to begin their journey into web3, but feel like there are too many barriers to entry. Something that one artist in our network said to us recently: “Joshua, Brandon you don’t get it! It’s not like anyone with a couple of dollars can participate in NFTs”. We think about this all the time and how much work needs to be done to make this world accessible to everybody. In reality, it cost us about $4 to mint PixelRug and Hashanty on Hedera (you can mint 10,000 NFT collections for $78). Through their own creations, we think the HIP-412 standard offers a new incentive for the Hedera NFT community to display through project innovations by creators that the NFT game has changed and evolved.

There’s a great article that outlines all of the things we didn’t really talk about and how our community has grown. Since the release of HIP-412, we’ve seen other creators minting multi-file NFTs and as collectors ourselves it’s been so fun to receive these bundles and unpack them in your wallet like unboxing a unique surprise. We believe these new standards will have a ripple effect on other blockchains and hopefully bring the entire tokenized art world a little closer together. At the end of the day, there are so many reasons to love Hashgraph as a technology, but it’s always the art that connects us as the industry advances. As time goes on, we will see use cases and art on Hedera beyond what we could have ever imagined and watch the barriers to entry fade into the background. We encourage everyone to begin using the unique tools already available in this space; they are ready, like a blank canvas waiting for the artist to pick up their brush and begin to paint.

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