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Episode 12 – How To Make an NFT (and Sell It, Maybe?)

Watch 19 min

“So you’re an “artist,” well actually you’re a dreamer and you’re just 100,000 Instagram likes away from stardom. King of the Artists Sir Beeple of Profanityshire has flipped the bird to the art cognoscenti by auctioning his art as an NFT for $69 million on his first NFT -and now there’s a conveyor belt of of celebrities, artists and minor talents filling up the internet with non-fungible stamped images, gifs, music, recycled bath water and more and you… you are emboldened, you think, this is the answer this is what we have been waiting for all along, this is how I rise to Clout Heaven and goddamit, you’re going to mint an NFT

Easy peasy. 

Except, wait, that last part, minting… what, like actual mints?, how do you even do that? What platform should you use? Is the art actually on the blockchain? Is it secure? What does it cost? Will I make millions!? 

Big questions that demand… well they’re not big questions, there’s just a lot of them aren’t there. But let’s see if we can answer them for you, help you mint your first NFT and maybe, maybe just maybe, make an actual sale. . 

Presented by Ledger and the Defiant, this is School of Block.

In episode 11, we dug deep into the why behind NFTs, or non-fungible tokens, exploring how some people just want to collect a piece of history in the form of digital art, while others truly understand the power of NFTs through the functionality that can be built on top. An NFT, see, is a unique digital asset that can act as an access pass for perks, events and much more. 

Well if it’s a physical piece of artwork, you’re going to have to get it into the computer somehow. What we mean is making some kind of digital representation, so a picture will do. Let’s see if we can do a little bit better than that shall we?

VO: Step 1, we need an idea. Green screen – check. Inflatable unicorn – check. Cowboy hat – check. Lack of dignity – never, always cool as hell. Greatest film ever made. Easy. Dr. Strangelove. Slim pickens. And now we shoot.


Next. Add a background. Add sound. Make it a GIF and we are good to go. 

Once you have that digital version of your art, you might decide to animate it in Photoshop if that’s in your repertoire. 

*Robin turns his static JPEG into an animated GIF* 

So we’ve got our animated art… Now what? 

For starters, there are an ever expanding universe of platforms for minting and hosting NFT art and each with their own specific experiences, expectations from artists and art lovers and costs. Probably the most popular of the NFT marketplaces are OpenSea, Nifty Gateway, SuperRare and Rarible. What’s important to note here is that these platforms access your Ethereum wallet so any NFT you hold will be viewable and tradeable no matter which platform you use. So, what you’re looking for is discoverability, how easy is it to find great work or be discovered yourself? OpenSea is the grandaddy OG of NFT marketplaces and it’s the place I usually go first to look for a deal. It’s kind of the eBay of NFTs. But because of that it can be hard to cut through the noise so we’re going to look at a different platform today, and that platform is Rarible. 

What we want is a nice, straightforward minting process and that’s where Rarible shines. 

Going to, the home screen is pretty obvious, there’s two buttons, either Explore – so go look at other people’s NFT art – don’t need that pressure – or Create. We’ll click Create here. And then on this screen, we decide whether we want to sell only a single version of this bad boy or whether we want to make a series of editions. 

For this experiment, I think I’m going to only make a single NFT. Because based of what I know about art, bubbles and beanie babies – Daniel, maybe you come in here and give him a side eye, like saying he knows nothing about those things – if there’s only one-of-a-kind, people will be clamoring over each other to get their hands on this rarity. 

To take this step, you’ll want to make sure your MetaMask is on the main ethereum network, not a testnet network like Ropsten or something like that. You can use several other Ethereum wallets, like Formatic, but MetaMask is, by far, the most popular. And yes, you’re gonna need ETH, from what I understand, a good amount of ETH. 

So then you get taken to this page, where you upload a picture of your art, give it an alluring title and description – Robin chooses something here – decide what kinda royalties you’ll take on its sale – Robin choose something here – and set a price. Let’s say $100,000, you know, start small. 

And then you push Create. 

This part of the process typically gets skimmed over, most YouTubers and commentators just say something like, “And then, yeah, launch it to the blockchain” as if that really explains anything. It makes sense, though, with these marketplaces, that step is obscured, so it really does seem that easy. 

But let’s dive a bit deeper here. What is actually going on behind the scenes? 

Well, Rarible (and whatever other platform you might use to mint NFTs) makes two different transactions.The first transaction is a contract creation transaction, which sends the smart contract containing the logic of how the token works, to the blockchain. Miners then do their thing to authenticate that transaction and commit it to the blockchain. Then another transaction is sent that specifies the number of tokens that should be attached to that smart contract and who the owner of that contract is. Once that transaction is approved by miners and committed to the blockchain, your Ethereum account is updated to include this asset. 

The asset in question comes in one of two forms – and ERC-721 token or an ERC-1155 token. 

ERC-721 is a token standard for absolutely one-of-one non-fungible tokens. ERC-1155 is a newer token standard that allows for the creation of NFT collections, whereby there are fungible and non-fungible aspects. For instance, the editions in the collection are somewhat fungible in that they’re the same art but have different edition numbers, similar to traditional art prints – think 1 of 20, 2 of 20, 20 of 20. But each edition would be non-fungible with a completely separate collection of NFT tokens. 

As for the NFT itself, then, what actually is it? Well in some cases, it is just a crypto token with metadata attached, that metadata pointing to where that image or animation or song is hosted – in most cases, that’s to a website. 

Although, there are other NFTs that do a few more tricks. 

Take Autoglyphs – Autoglyphs are generative art pieces, generative art meaning art that is at least in some respects created with an autonomous process. Inside the Autoglyphs smart contract is the algorithm that creates the artwork and so, as it creates new tokens, the art is actually encoded there in the metadata. In this case, then, the artwork itself is actually on the blockchain. 

OK, so now that we actually know what’s happening, that might help us understand why minting an NFT costs money, so much money right now, but any money at all really. Because there are so many people currently using the Ethereum network, it’s dealing with some congestion issues and as miners put in work to authenticate these transactions, they get paid, in ETH. And we, as NFT artists, aren’t only dealing with other artists, but also a ballooning number of DeFi traders and even gamers. 

So let’s click Create and see how much the fees are today. 

When I click Create, my MetaMask pops up and informs me the gas fee – HOLY SHIT, X ETH, X DOLLARS, good thing we’re gonna sell this bad boy for thousands more. And then asks me to confirm the fee and the transaction. So we hit Confirm and… goodbye money.

Once that minting transaction is sent to the blockchain, you’re then asked to sign the sell order, which also brings up MetaMask for your confirmation, just confirming that you are, in fact, going to sell your magnum opus. 

And now, it’s confirmed, it’s in my collection, I am fully a famous NFT artist!!!!!

Once you’ve created your NFT, you can click on it and get a full view of the piece, clicking on the tabs and seeing some data. Under owners for instance, it shows one owner, myself, it’s history, minted 1 second ago and under details, it says the rarity level is Unicorn. Not sure I understand what that means but unicorns are rad so that seems good. 

Once someone buys this bad boy, the owner and history will obviously change, showing the NFT trading hands, and by hands I mean, Ethereum addresses. 

So now, we wait for some art connoisseur to see my genius. 


While creating our first NFT, we’ve learned a few things about NFTs – firstly, like many things crypto, there are a plethora of options. This is all new technology and new territory and artists and entrepreneurs are experimenting with all kinds of different mechanisms for creating, hosting and selling NFTs. 

Right now, the fees associated with minting NFTs are pretty high – because the Ethereum blockchain is being used A LOT, a kind of good problem to have actually – so if you’re thinking of becoming an NFT artist, know that you’re gonna have some upfront costs to get started. But you’ll be one of the early adopters, investing in a new technology that’s growing and evolving everyday and is sure to change the art world, no matter what your medium is, forever. But we’re seeing fast alternative L1’s like Polkadot, Solana, Near and Algorand really starting to pick up major traction now and that means it will be both fast and cheap to not only mint and sell NFTs but to add additional functionality to them that won’t cost an arm and a leg for users to interact with. And if you’re wedded to Ethereum then you can always jump across to L2 solutions like Polygon and just for fun, let’s do exactly that using the Polygon NFT minter.

ROBIN DEMO POLYGON MINTER. (timer, clock on  screen)

You’ve been watching School of Block, presented by Ledge and The Defiant, demystifying decentralization, on block at a time. Don’t forget to subscribe below and drop us a like if you came out of this ready to create your own NFTs. Here’s to your financial freedom. 

What was cut, but can be brought back in if you want and have time: 

While we wait, let’s talk about costs. Some platforms offer a couple options. OpenSea, for instance, allows you to mint NFTs individually and when you mint individually, you set a minimum price and real auction bidding can occur on that piece. You can also bundle your NFTs into a collection, but then you have to set your actual price per NFT, as auction bidding can’t occur here. 

Minting individually means paying the hosting price each time. When bundling NFTs, the hosting fee is only paid once for all NFTs in the collection. 

*Robin checks back to see if anyone has bought his art*

No one! NO ONE!! – Bangs keyboard. 

Ok, we’ll wait a bit longer, no hurry, no hurry for greatness. 

I mentioned some stumbling blocks for NFTs previously, but those aren’t the only ones. Obviously, a big one we talk about in many of our videos is scalability. Because the Ethereum blockchain is hopping with activity, the costs for creating NFTs and on the other side, purchasing NFTs are high. This keeps many an NFT enthusiast out of the market. Many people aren’t going to pay a couple hundo in ETH for a piece of NFT art and then also pay the same amount in gas fees just to purchase the dang thing. It’s why NFTs have started popping up on a bunch of other blockchains recently and why Dapper Labs built their very own blockchain, Flow, to host it’s NBA Top Shot digital collectable basketball cards. 

*Checks computer again, no buys*

All this masterpiece-ing, I think I’m wiped for the day. And surely, overnight, someone will have bought my NFT. 

*Cut to Robin laying in bed, drinking camomile tea and getting ready for sleeeeeeep… minting*

It’s called sleep minting. Shhhh… 

*Robin roused from a bad dream*

Ahhh, Jesus, sleep minting!! 

Sleep minting is not a lovely dream of unicorns and rainbows. Sleep minting is a nightmare, an impersonation attack making its rounds in the NFT hype cycle, whereby an NFT creator assigns their artwork to another creator. 

This happened recently to Beeple. A trickster hacker and current NFT hater going by the pseudonym Monsieur Personne created and NFT of the “500 EVERYDAYS” artwork using the ERC-721 standard, but customized the contract with a bit more logic so that it could mint under someone else’s account, that being Beeple’s. 

In that way, the NFT looked like it was minted by Beeple – and seeing that he sold the first “500 EVERYDAYS” digital art for $69 million, this second edition might could fetch a number pretty close to that as well. 

The only way to tell the difference is by looking closer at the origin transaction. Under transaction details, the ethereum address linked to the “From” line cannot be manipulated as the transaction must be signed by the sender’s private key. 

Yet, linked to the “Tokens transferred” line, that “From” can be manipulated to say whatever the hacker wants, as it’s reliant, not on the blockchain and its whole host of miners, but on the specific implementation of the smart contract. 

Monsieur Personne was also able to make it look like the NFT was held by Beeple, briefly, and then sold by Beeple. 

While digging into the blockchain data reveals the forgery – you need to make sure the mint transaction sender and the NFT sender line match Beeple’s correct ethereum address – this takes a good bit of technical know-how, which is probably way out of reach for many n00b NFT enthusiasts. 

But for Monsieur Personne, the idea wasn’t to REK n00bs but to “show you just how ludicrous the situation with the NFT hype is,” according to his April 4 blog post. Other hackers, though, they might be out for much, much more with this attack.”

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