The no bullshit, straight to the point and essential blockchain guide for NFT artists

Disclaimer first. This article is not financial advice and you agree that by following the instructions explained in this article I will not be held responsible for any lost funds in the process.

Test it out with small amount first, see whether it works for you or not.

With that said, let’s get on to it, shall we?

Polygon on OpenSea

As Polygon (Matic) chain supported on opensea, comes good news and bad news.

Good news. There’re literally no fees on OpenSea if you use Polygon. Polygon fees are so insignificant OpenSea actually cover them. Both for seller and buyers.

Imagine buying ETH NFT which priced at $1, Ethereum gas fees are now ranging from $50–$100, at some points it actually even reached $1000.

Polygon eliminate that kind of gas fee problem for sure.

Bad news is, there’re literally unlimited copymints, scams and low effort collections posted on OpenSea within Polygon chain, because there’re simply no cost barrier to upload/mint anything on it.

Good news is, legit artists also have lower barrier to mint their works. So they have better option to make living out of their pieces.

Bad news is, they often don’t understand how blockchain works or even how to cash out their earnings from the blockchain.

Good news is. I’m here for ya.

Why Fees? Gas fees, Transaction Fees, etc?

Nothing is free on this world, that is including stuffs that you do on the blockchain; buying and selling NFTs or mere transfer between wallets (even your own).

I won’t go further deep into the technicalities of these fees within blockchain, just simply think of it as admin fee when you do the conventional bank activities, or even tax. You just have to deal with it.

Nothing is free

Some chains cost lower than the other, some cost ridiculous high fees. And ETH is being highlighted for this matter.

The very issue that makes ETH fees so damn high is that fees are charged with ETH in mind, gwei; or giga wei a small unit of ethereum. Then there’s wei, 1/1,000,000,000 of gwei.

Ethereum fees were very reasonable when it was valued within hundreds of dollars. But definitely not at 10x plus on early 2021, which of course raise the fees by at least 10x as well.

A Change for Chain and Changes

At this point we should be agree upon one thing, and you should keep this in your mind : all activities on blockchain will cost fees.

So moving away from ethereum a bit. Of course you know Ethereum and Polygon aren’t the only chain out there. There’re also BSC (Binance Smart Chain), Solana, Tezos, Ada (Cardano) and so on. Those are running on their own chain.

Most of the time, in order to do anything at all within a chain, you need to have certain amount of the native coin available within the chain to cover the fees.

For example, you’ll need Ethereum in order to transfer USDC to another wallet to cover the fees. Even if you have 1,000,000 USDC inside your wallet, but you don’t have any Ethereum in it to cover the fees you won’t be able to do much with your USDC.

Same thing with BSC, you’ll definitely will need to have some amount of BNB in your wallet to cover the fees. Even if you don’t deal with BNB much.

For example, when playing the game CryptoBlades, which uses BSC and SKILL token you’ll need to have BNBs in your wallet to cover the fees, since SKILL is a token within the Binance Smart Chain.

Same thing with Enjin (ENJ) on which I experienced with Lost Relics. The game mostly deal with Enjin. But since Enjin is a token that live on Ethereum chain, I need to have some Ethereum in my Enjin wallet to cover the fees. Even converting Enjin to Jumpnet Enjin (JENJ).

So many chains out there

Pretty confusing stuff huh? Don’t worry, you’ll get use to it.

Here’re some important highlights so far :

  1. Make sure you know exactly what chain are you on
  2. Having native coin/token on that specific chain all the time is highly recommended to cover fees (BNB on BSC, MATIC on Polygon, ETH on Ethereum, ADA on Cardano and so on)


Polygon Logo

In order to avoid confusion please keep in mind that Polygon = Matic. They just did a rebranding back then. So I will be switching between two names for the chain later on but they should refer the the same chain. Polygon/Matic network however, have their native coin named “Matic”.

With the Polygon chain being free (minting, listing, selling, buying, etc) on OpenSea, and a lot of newcomer NFT artists without any background in cryptocurrency knowledge/education resulting the misperception of everything on Polygon is free.

Hate to break it up for you : it is not.

As been discussed before, Polygon fees are very miniscule so OpenSea covers the fees for the users (both sellers and buyers). Probably for promotion or an attempt to popularize it. Because on the other chains like Solana and Tezos for example everything still cost something, even if they’re very small, insignificant amount.

Also, another issue is that some insisted OpenSea is keeping their WETH in somekind of custodial wallet that OpenSea hold, since the balance and number of sales don’t reflect on their Metamask, when they haven’t added Polygon/Matic mainnet to their Metamask.

This misperception are quite common because some artists that publish/minted their works on Polygon actually don’t realize they already have hundreds, sometimes even thousands dollar worth of WETH (Wrapped ETH) within their wallet from their sales and don’t have any clue on what to do with it.

Fact is, any sales you made within opensea should be directly transfered into your wallet, that is why OpenSea requested you to connect your wallet. They immediately take their cut (2.5%) straight from every sales happen and transferred the rest directly to your wallet. You just don’t see your WETH Polygon balance in your wallet yet.

Adding Polygon Mainnet to Metamask

We will discuss adding only Polygon/Matic mainnet to Metamask on this article. You can always google “add x Metamask” with x being the chain you want to add to metamask and look for the official chain page (and make sure it’s the official page) to show you how to do it.

However, Cachemonet from r/nft showed the easiest way to do it; go to and scroll down to the bottom you should see this button :

“Add Polygon Network” button at the bottom

After you click the “Add Polygon Network” Metamask should then give you this prompt :

Add network prompt on Metamask

Now you should have “Matic Mainnet” (remember, Matic = Polygon) as an option when you click on network selection (the dropdown menu next to the Metamask’s Fox logo).

Matic Mainnet option is now available

If you choose Matic Mainnet it should now show your current MATIC balance in it. But where’re all the hard earned WETH you have?

For that, you need to import the WETH token contract address now. You can find it here :

Copy the “Contract”

It’s the top result of google from looking up for “polygon weth contract address”.

Here’s to make it easier for you :


But please do double check everything.

Copy the contract address of Polygon WETH, click the “import token” button on Metamask (make sure you’re in “Matic Mainnet” first), paste the address in “Token Contract Address” field.

The rest should be filled automatically (symbol and decimals) if you done it correctly. And if they’re correct, your WETH balance should be the same both on OpenSea and your Metamask connected to it.

So what to do next? On to the next chapter.

How do I Buy Lambos With the Polygon WETH I Earned from Opensea?

Bad news first. Lambo dealers don’t accept WETH for payment nor Metamask for payment method at this time of writing.

Good news is you can cash your WETH into fiat/hard cash(USD) to buy the Lambos you want or deposit them to your conventional/fiat bank account.


This is quite tricky part to explain. So I won’t go further deep into technicalities here. At this point you should understand when you sold your stuff on Polygon at Opensea, oftentime you will receive WETH on Polygon on every sale.

That means : your WETH from your sales is currently resides on Polygon mainnet, not on Ethereum mainnet.

As have been explained in the previous chapter, Polygon’s native coin is Matic. On which I assume most (read that again; MOST, NOT ALL) cryptocurrency exchanges usually support coins on their native chain.

This don’t just apply to Matic but as far as my experience so far, Tezos and Solana as well.

At least I confirm 3 exchanges so far : (not supports Matic on Polygon

Coinbase do not support Matic on Polygon.

FTX do not support Matic on Polygon.

Coinbase and FTX only supports Matic on ETH Mainnet is cool; they support Polygon network for Matic deposits

The rest is for you to find out. Do your exchange support Matic on Polygon or not? If you do have insights about this please write down in the comment below.

Anyway, so if you do use, you’ll need to convert those WETH into MATIC, but still using the polygon network while doing so.

Here’s the TLDR version of it :

  1. Swap WETH to Matic on Polygon
  2. Transfer Matic on Polygon to an exchange
  3. Sell Matic to fiat and cash it out
  4. Buy Lambos

And here’s the long explanation along with the bad news that comes with it. You can use defi apps for swapping needs. For this matter I used Sushi Swap ( for converting WETH to Matic on Polygon.

The bad news is, like have been explained in the previous chapters, you’ll need to have some amount of Matic in your wallet to do anything. Swapping included.

So, go get some Matic first if you don’t have any. Anything more than 1 Matic should be enough as the transaction fees on Polygon usually just cost just around 0.000x Matic.

Where to get some Matic if you don’t have any? There’re couple of ways; buy it from an exchange, find some Matic faucet, buy it directly within your wallet (Trustwallet or Metamask mobile) or even ask people around to borrow some Matic.

Some people are actually kind enough to lend you some Matic to cover the fees since the fees are ridiculously cheap, you can go very far even with 0.1 Matic in your wallet to cover the fees.

Second bad news as been described before; NOT ALL exchanges support Polygon network deposits even for Matic. Please double check the network when depositing, otherwise your monies will stuck in a limbo, unretrievable and your exchange usually will refuse to retrieve them for you.

So on to the swapping step by step. Open up Sushi Swap page (

Sushi Swap page (

Make sure your metamask is on Polygon/Matic Mainnet, click “Enter App” button. Then the rest should be self explanatory and straightforward.

Sushi Swap’s Interface

Click “Connect to a wallet” button on top right of the page. Metamask should then open a prompt to request your approval to connect to the website/app.

After your wallet connected choose “Swap From” and “Swap To”. “Swap From” field should now reflect your balance you have within your wallet. Relevant to this article, Swap From should be “WETH” and Swap To should be “Matic”.

Enter the amount how many you want to swap into Matic. If this is your first time doing it, I recommend you to test a small amount first. Not all your balance.

After you done swapping, you can now do whatever you want with that Matic balance. Cash it out from exchanges or buy stuffs from crypto and NFT space or buy lambos, have parties whatever.

But I would recommend to leave at least some amount of Matic in your wallet to cover the fees you might stumble upon in the future.

Which color of Lambo would you buy?

So What About Exchanges That Don’t Support Polygon Network?

You’re out of luck. I would guess you’ll have to bridge and take out your ETH directly from Polygon to ETH (or some other chain that your exchange actually support, but usually it’s ETH) and bridging would cost a lot of ETH (depending on the gas fees).

Basically the process would be like this :

  1. Unwrap/swap WETH to ETH on Polygon
  2. Move the ETH from Polygon to ETH Mainnet

Swapping WETH to ETH and taking out the ETH from Polygon won’t cost much but the receiving end of ETH Mainnet that’s where it would cost quite a lot.

There’re a lot of defi apps that specialize in this bridging needs, but I don’t have much experience with them. With that said, bridging would also require another full article to discuss.

Nevertheless, if you understand this article and how chains/coins work in general, wouldn’t be difficult for you to DYOR further about bridging.

Good luck.

Slow roasted nuts, for your pleasure.