Migration of The Underground Sistine Chapel NFTs to a custodial smartcontract

Last summer a debate was launched in my Discord community about the lack of decentralization of the NFTs of The Underground Sistine Chapel.


As a reminder, The Underground Sistine Chapel is my biggest project to date. It's a modern version of the Sistine Chapel painted during 5 months in a former gold foundry near Paris, ended in Dec 2020. I did hundreds of NFTs from the work in early 2021, all infos here. The debate was very instructive and benevolent, the people who initiated it were among my most involved NFT collectors for a long time so I had to listen to them without a doubt.


In fact, they highlighted a lack of ownership of the smartcontract and a lack of decentralization of the metadata storage on The Underground Sistine Chapel NFT collection. This issue was coming from the fact that it has been minted on OpenSea StoreFront shared smartcontract. Because I minted the 404 NFTs of the collection back in May 2021 using the "lazy minting tool" on OpenSea. Since 2019, I was minting my NFTs on OpenSea and until then I didn't heard anyone complaining, so I tried to understand what changed... Back years ago, the minting tool on OpenSea was pretty cool; it was minting direclty the Non Fungible Token "on chain" and the creator was the only owner of the smartcontact. But after that, with the 2021 hype around NFTs and the historic $61M Beeple sale, all eyes was on NFTs, so OpenSea had the idea to do a smart marketing move for the large public by creating the "Lazy minting" tool that let their users "create" NFTs for "free" (technically the minting of the NFT occurs when someone buys it. It's the buyer that pays the minting fees, not the seller). This was looking cool to onboard a new large audience into NFTs, but it wasn't good for professional creators like me, who cares a lot about the ownership of the smartcontract and the decentralization of the metadata storage for the long run, even if it cost some significant fees to do it.



The issue was that the Shared Storefront smartcontract was owned only by OpenSea. Our 404 NFTs of the Chapel wasn't really owned by us, the artist and the collectors. Thus it was mixed with 270k others random NFTs created with the same OpenSea smartcontract. Worst: The metadatas (Images, videos & text) was stored online on AWS (Google owned servers), which was a great lack of decentralization and put the metadata at risk. At first, I was personnaly against any migration of the smartcontract to avoid confusion, I was very busy dealing with changes happening in my life... but after learning about all these issues, it was a bit too much and I couldn't ignore this. We had to take action as a all, mostly because The IRL (In Real Life) Underground Sistine Chapel was painted in an ephemeral place that will dispear one day, and NFTs where made to turn it eternal in the digital space.

We wanted the Chapel NFTs been eternal, but it wasn't.

To fix this, there was few problems to solve. All the NFT collection has been already sold during the summer, there was 220 owers for a total of 404 NFTs. Some of them bought their NFTs on the secondary market, few had paid large sums to get their NFT (up to 25 ETH), so I couldn't take the decision alone. I wanted the large majority of them to participate to the decision by voting Yes or No to the proposal, after aknowledging the Pros & the Cons.

The pros ✔️ where:

- Its own smartcontract, which will give more value to the project long term and appear as its own collection on other platforms

- Decentralization of the metadata on IPFS, not attached anymore to the OpenSea servers making it censorship resistant

- The contract will be open sourced on Etherscan making the HD images of the NFTs easier to download

- Communicate about the "Resurrection of the Chapel" and we would be the 1st NFT community to do this. Also, it opens a larger debate about the longevity of NFTs in the long run

- Could be good for our community to do something as a group and work all together to improve the project

- Allows for better sorting of the NFTs regarding the metadata, which would be exactly the same as before (Angels, demons, chosen, damned, apostles...) but easier to be browsed and visualized in our future marketplace

- Better compatibility in the future to build projects around, give exclusive access to community socials for the NFTs owners and create a Marketplace similar to Cryptopunks, which will be a great tool to browse and see all the statistics of the collection

The cons ❌ where:

- Loss of the original minting date of the collection in early 2021 (May 23, 2021)

- Also loss of the sales volume of the collection on chain (~800 ETH), loss of the old transcations on chain, loss of the old bids, loss of current bids at the snapshot time, loss of current listings, views, likes, unlockable contents

- Fees cost for the artist. Doing a new smart contract would cost between 3 to 10 ETH (depending on the gas price and is based on the contract deployment fees + the mint of the 404 tokens)

- Security. We needed a maximum security aspect with an audit of the new smart contract code and no mistakes in the snapshot to be sure that each collector has their new NFT minted directly to their address in the best conditions

- Nobody has done that before... so we had to be very cautious and make no mistakes during the migration

- Some of the NFTs of the Chapel was fractionalized on Unicly through uPBOY. We had to find a solution for those NFTs to be able to follow the migration


With the help of Jolan, a talented Web3 Engineer and one of my early NFT collectors, we created a voting Dapp (Web3 Decentralized application) that let the owners to vote by connecting their wallet containing the NFTs, that way we was sure that the real owners could participate without any fraud. I didn't saw anything similar in the NFT space before that so I did't knew what would happen...



The vote ratio was 1 NFT = 1 vote. The vote lasted one month (from Nov 21 to Dec 21). We shared the launch of the vote on my private Discord & Telegram groups and on my public socials:

The results of the vote was amazing: more than 3/4 collectors voted! With a total of votes: 310 / 404 (76.7%).


YES total votes: 288 / 404 (71.2%)

NO total votes: 22 / 404 (5.44%)

The majority of the NFT owners voted YES (71.2%) for a new custodial smartcontract.


After the positive vote, we decided to migrate the smartcontract on new year's evening by doing a snapshot of all the NFT owners addresses without telling anyone. Each collector received a new NFT in his wallet and the old one was hidden from OpenSea and any related metadata (images & text) was erased with the help of OpenSea support as we asked them (Many thanks to Kartik).


Big thanks to Jolan for doing all this sucessful work of migration and building the Dapp! Also thanks to @edgarallenpoe & Artefact.eth for helping on registering all the voting addresses and reaching out the collectors! Also a big thanks to all of them because there are the ones who initated the debate around the migration this last summer!

Finally, we have our own custodial smartcontact with the metadata fully decentralized on IPFS!

Now we can follow all the transactions and see the owners distribution chart on Etherscan:


The Underground Sistine Chapel NFTs ⛪ can now last forever! ♾ Many thanks to all those who participated to the debates & the vote


You can browse all the new NFTs by clicking on the image bellow or directly browse the collection on OpenSea, Rarible or LooksRare.