Mike Tango Bravo / DCxPrague

Transcript

uh so my name is Mike uh Mike Tango Bravo and I make uh wine in Argentina in a I have a small Winery and Vineyard and you say well what does this have to do with uh what we're doing here today um basically I've been working on the open Veno project um since about 2017 and we're using a lot of different tools uh to tokenize Wine to do transparency and to do uh traceability so I'll just describe briefly how each one of these work by the way at the end of my my talk um we'll be doing a wine tasting out on the in the main room out

on the balcony and uh I brought a bunch of bottles I dragged them up the hill this morning so yes absolutely proof of work so please come and and have a taste these are some we we'll do a a what I call a diagonal tasting it's a vertical tasting meaning one that we're tasting different years but these are all tokenized wines uh we started tokenizing our wine in 2018 and now we're opening up to other wineries um and basically most of them starting in Argentina but talking to wineries in in different parts of the world uh to open this up and I'll I'll describe how this works so essentially we're doing tokenization we're not doing

a a non-fungible token this is just a it's a fungible rc20 token uh one token is one bottle of a particular vintage and this is how we're creating liquidity uh with liquid and uh if you think about it wine is a super interesting product for tokenization and basically for three reasons um and I'm not talking about specific like Library collection wines like there's a bottle that I have from 1964 from uh Chait and okay that's that's a whole different thing that's a nft Collectibles art I'm talking about the wines that we produce every year in a winery so uh the three things that are

really interesting for wine to use as a real world asset for tokenization is um built-in scarcity so when we create a when we Harvest grapes and ferment and make a new vintage there's only x amount of wine for that x a number of bottles it's a highly regulated industry in all parts of the world because it's food and it's alcohol and it also has a lot of cultural attachments so it's not like you can easily go and make more bottles of the 2018 without committing serious fraud right it's a it's a pretty controlled uh element in itself uh the second thing that makes it really interesting for tokenization is

that it's a product that requires some time time before it's really ready to drink and it gets better over time but not infinitely right and it's also not linear and so some wines have a uh could be you know from good to Great to no longer enjoyable could be two years or could be a 100 years and there's everything in between and there's all different kinds of wines that have that so I went to go visit a winery inesa LA frona and on Lucia in the south of Spain and they had a giant Warehouse full of bottles that are 100 years old right Sherry has a really long age to it but a

lot of other wines don't have that and so that Dynamic of is this wine going to be better has a lot of interesting speculation and the third thing that makes it super interesting for tokenization oops is uh is the elasticity and price right you can do a 100 Point Beer like the world's best Speer and you're not going to get $100 a bottle for it but people don't bat an ey at paying uh three uh figures four figures for the top wine right so those three things make it really interesting for uh for tokenization I'll describe how that works briefly um then we get into the options uh the questions

of traceability and transparency in the case of Trace uh traceability what I really want to know is who is drinking the wine and what do they think about it because today the way that we uh evaluate a wine is uh usually there well there's a few ways but the main way is I send some bottles off to an expert um they do you know there's some very famous noses out there uh Jon Robinson Robert Parker the the the classic uh critics and sometimes it's free sometimes it's not I send them a bottle and they're going to open a bottle and have two or three uh tastes

of one glass of one bottle probably in the middle of 200 other bottles that day and say this is a 95 okay and give it some sort of points that's fine but it's very anecdotal it's very subjective and it's also uh open to fraud cuz who's to say that the bottle that I sent them with the label and Cork and everything is actually the same wine that you're going to get in the shop right so there's a there's a question about about that the other way of doing it is saying let's do a Trip Advisor crowdsourcing of of opinion and you have an app in for wine world it's vivino is the most popular app and people can say this is three stars or five stars and qualify it

the problem with those apps is that you're asking for somebody's opinion uh and intellectual effort in exchange of nothing right and so like in the case of Trip Advisor more often than not people are using that as a way to punish uh a bad place that they went and not actually making a good review because what do they get out of it right there's very little um so we change that up around and then the third part has to do with transparency and this is really how we change the way that we certify uh the the qualities of a wine now more and more with every product that we're out

buying we're looking for things on the back label is it organic is it sustainable is it carbon neutral is it fair trade is it X number of qualities in the case of the wine world where we have 70,000 plus wineries so it's a very atomized industry representing a $400 billion industry um there's also lots of attributes like what grape is it what region is it from is this an oak is this this wine maker is it single Vineyard is there's a whole bunch of other characteristics how do we know that these things are true that the the Winer is not lying about it um and how do we solve this problem we call biod digital certification for

this and the the problem basically the alignment problem there is today is that if I have an organic Winery uh which is my case I planted grapes in 2003 in mendosa in Argentina wineries called Costa Flores the one we're going to drink afterward um basically for me to certify I call a company a certification company and once a year they come out to the vineyard out to the to my house and drink coffee and say so Mike did you spray any pesticides on your Vines this year and I said no I didn't I said oh great did you uh could you show us some receipts of stuff that you bought that you need that doesn't

include anything you're not supposed to buy yep here's some receipts uh show us a worklog of the things you did this year and I showed them an Excel spreadsheet that I put together the night before and a couple things like that right it's pretty easy to to do at the end of the day but the problem is that the the certifier wants to give me a yes because if they give me a no they lose a perennial customer okay now I'm a tiny Boutique wiy nobody cares they could reject my certification but if I'm a big Winery I represent a large percentage of their invoice uh they're never going to give me a no they're always going to find a reason to certify me right and so it means that it's very

easy to cheat H it's almost becoming more and more meaningless um as we go forward so those are the three problems from the perspective of the winery the consumer the supply chain uh how do we resolve it tokenization is pretty straightforward in this type of a conference I don't need to explain it but basically we harvest the grapes in in South America we're harvesting in March April we're uh doing our fermentation following a process that we've been doing for the past 10,000 years um so the end of April we know how many liters of that wine there is this is also something that through a you know in the case of Argentina there's a national wine board and every country has their different ways of doing it but

we basically have to say in this tank there's 7,500 lers of Malbec ptio ceso blend from these uh through different Vineyards and here's some traceability so that's already integrated in that right so as soon as we know the amount of wine there is we do a vco a vintage coin offering and the uh we've been doing it every year on the 6th of May uh this is our sixth vintage to do it and basically we put up uh for sale in a crowd sale uh on a contract um we've been doing this on ethereum mainnet obviously this is is a problem we're now switching over to optimism as an L2 for uh for the wineries going forward uh

because of gas fees but essentially we put up 50% or up to 50% of the tokens in a crowd sale at a very low price at cost price and this is basically an interesting from the wineries perspective because they can immediately recoup some of their investment on something that usually they're going to have to wait at least 3 years 2 three years before those bottles are ready to consume um from the 6th of jun of 6th of May to the 25th of July we have this crowd sale running uh 25th of July we uh activated a liquidity pool uh we're just using uniswap V2 right now um where we put up 25% of the tokens into liquidity pool

and now anybody that wants to continue buying the tokens or sell the tokens or do whatever they want has a way to buy and sell and the point being here that yep it's another token it's a small volume small liquidity token but hey it's backed by a bottle of wine and so it's never going to go to zero and it's never going to go to a million right it's going to find its spot which is basically what people say this is what this wine is worth right um so who's buying these tokens uh consumers people that are a lot of the people that have never been in crypto before they're like oh I want to find out how this works I'm taking a risk here but it's a bottle of wine I'll drink it um also importers uh Distributors uh retailers people that

say I could come in and out of these positions uh easily and once the redeem period is ready so in the case of my wines this is after 3 years but the tokenomics could be different for every Winery um basically they go back to the to our dap open Veno exchange and it can do a redeem and basically say how many bottles do you want to redeem uh give me your address and at that point we calculate uh what the shipping cost is going to be um and burn their tokens and send the bottles and so this uh is how we are uh over

time um reducing the pool of tokens we have a full life cycle in my case 10 years of validity so if you lost your wallet if you forgot about it 10 years goes by yep you lost those bottles um but it also means that because there's a relationship there you could say somebody you know we've had I've had a lot of people let's say hey I lost my wallet I bought these tokens I say do you know the wallet address I look I go yep it hasn't moved in 1156 days uh I know you or whatever I'll Shipe the wine to you so I could even respect that as a voluntarily from the Wier because we're talking about real people and a real product and we're using this as a

mechanism for uh for pricing and creating liquidity okay uh the second question about traceability I mentioned we do it with um today we're getting experts to qualify our wies essentially here what we're doing is putting on the back label a serialized QR code so every QR code is different uh and enabling somebody if they want to to read it scan it go to a site provide information provide feedback ask answer five questions about their drinking experience take a selfie with the bottle so super invasive in their done dinner but it's essentially becomes a uh we meant an nft for them um just this

afternoon we're moving this over to optimism and so it's a gasless transaction and uh minting in nft so it's kind of a pope token a poop token of your wine drinking experience what we're missing on this slide and what we want to add to this and the thing that actually makes it useful Beyond this is giving them an open V Dow token which will be releasing in next year now I'll mention the the construction of the Dow I think we're doing a dow that's completely different from any Dow you've ever seen in qu in in the reason of utility what it actually does it's not just managing the uh the treasury with votes of speculators but the idea the concept here is we want to say if you're going to share your feedback your information

good or bad um you should get something out of it right you've taken already the leap of ingesting into your body the product that I make and so I'm saying if you want to talk about it great we'll make you part of the organization you drink it you own it right that's the concept um so the last part which has to do with the transparency is what we call biodigital certification basically it's enabling a bunch of different data points that can come from iots from different sensors uh cameras images work logs Etc but the question here is basically for a winery that says Hey

I want to certify as organic I don't want to pay a third party that's what I described earlier right because that money that I'm paying to a certifier doesn't make my wine taste any better right so basically we have three pillars one is describing what it is the certification what is organic right it's 27 things these are things that are already most cases legislated or documented it's just describing them and uh in a concise matter the second is saying how is the proof of artifacts for this so how can they match this to sensor data to work logs uh to applications or things that can be provided in real time so it's not the

spreadsheet that I uploaded the night before uh it's an app that we give for the 25 different tasks that are happening in a Vineyard and in a winery throughout the year um it's a drop- down application very simple for pretty much anybody that's working in the wine industry to use you don't have to know anything it's like okay we're harvesting today we're pruning we're uh like I said there's only a small collection of things that get done over and over every year right so this is their way of proving what it is that they're doing but where it gets interesting is in the third stage so this is basically working with uh cletos and with the platform project that's called the badge that you might have heard of uh the badge doxyz and basically this is where the

winery says okay we want to be organic here's what organic means here's our arguments we're going to stake 5,000 during for 30 days and if anybody wants to challenge us on it you can also stake and you can upload your arguments your evidence of why we're cheaters and then we go to the Clos Court they vote on it and either I get the 5 ,000 back and a digital badge uh or I don't right so this is basically changing the Dynamics of certification so the idea is here it's not just something that benefits the wineries they do have the advantage in certain things like getting money in advance being able to have more flexible

pricing right right now when you set the price for a bottle of wine you're stuck in that price it's very difficult to change but if you could say hey this is Market driven it goes up and down this isn't me this is just what the world decided the price it's a legitimate real price you're paying the market price right um so there's different kinds of of benefits to this so the idea here obviously is to use the power of things that actually make sense to do on a blockchain on a public blockchain um couple of other different things we'd like to go towards obviously like everybody a more decentralized app I was just talking to Andre uh I didn't see us talk yesterday but about how you could do a more decentralized app but

one thing we are working on is basically what we're calling a netr brick but it's a Dap node I'm sure you're all familiar with dap node but it's basically a Dap node with the radio antennas for collecting Lowa and collecting 433 MHz is where we're collecting the data of the sensors in the winery and in the field so since there is an edge iot need for a device right could be a Raspberry Pi but since there is a need for some device in the winery we're saying well okay let's just create that black box device that's actually a ethereum node ipfs node um and collecting the the data that we're

publishing for iot um aggregated using a platform called blue.com uh on chain so basically the idea here is uh have they have have a reason an interest for actually running a a node it's not just like oh hey how cool to run a d node it's actually something that that makes sense to use it um and can be actually a platform for decentralizing the front end as well um and then for everybody that scans it and wants to get their poop token of their drinking uh session um their experience it's like a super easy way for somebody that doesn't know anything to minant their first nft of the the party that they're having

with their friends um so that's basically um how it works uh right now we're at the stage where uh I've spent the last six years putting this together based on on the stuff in my Winery we've been wanted to start last year with other Winer we pushed it back a year because of the merge and FTX and lots of bad press and basically the challenge here is not to obviously we're not doing anything super sophisticated here and minting you can imagine our contracts are pretty basic what's sophisticated is sitting down with the wineries doing a workshop we do a three-day Workshop or 4-day

Workshop we go okay how does this affect your accounting how does this affect your uh legal question how do you deal with your uh Salesforce how are they going to interpret it how does this marketing how are you going to message it how what's what's your landing page going to look like what's your tokenomics going to be uh how would this affect pricing of your current wines and so basically it's melding those two worlds of expertise and the wine world and and uh web 3 and saying okay here's a Playbook to do this and so what we want to do is that between five and 10 wineries in the next year um mostly in Argentina but not exclusively do some in Spain as well to do uh their tokenization um with the objective as of

a network effect to get to 300 wineries uh within 5 years um and this is all based on on doing a specific uh type of a da now I mentioned this before I know there's a lot of reaction today about oh okay there's so many things that can go wrong with the Dow um but basically the the if I had to to boil it down to an Essence it's not just about collecting people's money and saying here's a vote and you can vote on the protocol and decisions that are made with the treasury it's saying to the wineries you want to use open Vino uh to tokenize to do uh free self-certification and to generate all

this data from your customers it's free there's no charge for there's no licensing it's absolutely free but you need to be a member of the Dow the first 300 wineries here are some Dow tokens will invite you to be right you want to provide services you want to uh connect the Erp to support uh their Erp platform to support a different type of a currency or token or whatever you want to provide that service to wineries fine you need to be a member of the Dow um the and so with the the yellow quarter here basically a quarter of the tokens is designed to be the ones that we burning every time somebody scans a bottle for you drink it you own it and also for wineries that we're on boarding

as an incentive pool so there's actually a reason to be part of a gated community um you know be it uh Discord or whatever tool we want to use but basically saying if you want to use these types of tools you can have access to them for free but you need to be a part of the dowo of course being part of the Dow gives you a stream of the dividend of any of the uh income but it also um gives you some voting rights now exactly how we're going to do that that's what we're still working on but this is about creating utility for the token of the Dow itself um so it's not just about creating a another token to speculate with so I'll just give you an example

here this is a project that I've been working on for 3 years biofabrication and basically if you think about the wine making process um when you make wine you end up with a mountain of sticks every winter when you prune back the vines you end up with all the stems that you don't use and you end up with the seeds and skins that after the crush you have a big pile of this and there really don't have an application for any of these there's a couple things but for the most part they either get burned or buried or thrown away somewhere so what we do is take the we're basically taking the pruning shredding it to the consistency of like

a tea putting it into a mold inoculating this with the melium strain um that we've identified that works really well with this particular substrate and within 5 days you have a box that looks like these it basically looks like Styrofoam it's FY on the inside it's it's like glass on the outside it's quite rigid um it's lightweight it has a lot of the properties and it's basically three ingredients it's Vineyard waist plus mushrooms equals a box sorry no as soon as we we give it a 75 80° C heat and this kills the melium and it's also not a mycelium that's interested in

Cork right it's not a fungi that's a f yeah some could be but it's not a fungal strain that that has an effect on on cork anyway so here's an interesting thing to say okay this makes a lot of sense you've got this biowaste in a Vineyard um and we can make boxes out of it and by the way wine is grape juice plus yeast which is a fun fungus equals uh wine right and so we're just basically making the Box using the same ingredients right the same sticks the same pruning uh from malbe in my case end up being the packaging now think about this I can go to uh in in mendosa in Argentina and say

well let's find a big Warehouse buy a bunch of equipment go out and collect people's pruning materials from their Vineyards bring there process it come up with 35 different SKS of boxes have a big Warehouse full of boxes made out of melium hire some people to sell them sell them back to the wineries ship these big 3D boxes back to them and is that going to work well maybe it's not very scalable right have to do that in each country uh the second way is to say all right uh Winer if you want to use this we'll give you the information on how to do it and we'll hook you up with the people that provide the base spawn that

you need and set up the molds and everything but you need to sign a licensing agreement and for every thousand boxes that you make you need to pay us x amount and we've got a patent on it and everything well now I've just turned a company into a uh patent offenders and chasing you know paying a lot of legal fees and this is boring as well so the third way to do is to say okay anybody wants to do do this we will share this information on how to do it we'll have a community of the people that can provide the spawn because you don't need to have that set up in every one of the wineries right you don't need to have the person that designs or prints out the mold in each one of the

winery so you have the providers for certain inputs you have the myologist that are doing some support and some backend and say the only thing that we require is that you're a member of The Da and if you're a member of The Da then you can be within this gate Community um of of of providers and services and participated in it and that's how you fund this type of development so that's basically uh it we also do something called vop phonics which is kind of fun this is a uh analog synthesizer and based on the ARP 2600 which is from 1971 uh the flat panel in front of it is called a vop phonics and this is

something that uh F and I built basically what it does is takes the sensor data from The Vineyard that goes onchain so in this box there's a little uh node basically I'm reading the sensor data the on the on the left on I've got a some sliders and those are motorized so they actually move on their own and so you can map that to a different data so you could say uh one slider one is temperature that goes from 0 to 35° CSUS right uh which would be from 0 to 10 on the slider position uh

wind speed temperature uh humidity we have soil uh soil sensors throughout the vineyard all different kinds of things that basically are making these potentiometers move on their own and then put those into patches into an analog uh synthesizer so basically it's going from The Vineyard to the sensors to blockchain to venic and then you can stream that and you make a derivative evolutive music from uh Vineyard data from stuff on chain absolutely essential um if we're going to go to our final step of course which is to have um prepared everything for doing uh Winery

on Mars because we need red wine for a red planet so thank you very much this is a open me note there's some of our our data there if we have any questions and then I'll when we finish we'll be over here drinking uh for as long as you like what's the of shpp wine so the way we work with shipping so shipping wine the logistics of wi is very complicated right part of the way that the initial design of the open Veno exchange by the way not the current iteration but the initial one was a fork of unisox um and so when when Hayden and uniswap people did unisx thought this is

great but it's very easy to ship socks uh wine is heavy it's alcohol it's highly controlled so if you think about even in the EU the EU is a common market uh a common Customs Market except for alcohol cigarettes and fuel right now having said that you can ship a few cases from Spain to uh to pag and it's not a big deal but um if you're doing large volumes and the the customers going say Hey you have to import this into the Czech Republic so uh so basically the way it works is uh pricing is based on where you're shipping to and so for example as long as we have a importer in the US uh in

Brazil in Argentina uh one or two places in the EU um those marketplaces are covered and actually the the cost of shipping the the the wine from in my case Argentina to the EU we defined the price of the bottle as the vco price the Vintage coin offering price the initial price right this is really interesting because basically what we're doing is segregating the value of a physical object right you can't export at zero cost you have to put a price on something that has import duties excise taxes all kinds of things on top of that but the higher that price is the higher

the multiplier is so is but as long as we segregate the price from the physical object to the digital object to the Token right there is no import of the token so if the token is at $50 uh doesn't matter uh when we the delivery we're basically saying the Importer that we work with says okay we'll import these bottles uh and the Fulfillment is basically them receiving it shipping it to the the end destination to the consumer um but the base price which everything is taxed at is based on the initial price of the Vintage coin offering exactly it within within a

range where it's not so expensive to ship it I mean shipping so for right now we have my one is in in Barcelona where we're shipping it through um but it it could be through anywhere right so to ship from Barcelona to to to Prague is not such a big deal to ship from Argentina to Prague is huge that's like $300 a bottle right because you have to go through all the paperwork of importing exporting that particular bottle it's not just like shipping a pair of socks um but it does have an interesting effect in that uh I'm going to speak in Mexico next week and I have a lot of people that bought a bunch of tokens in Mexico and I don't have an importer in Mexico right but I can go to an importer

in Mexico and say Hey listen uh you've never tasted my wine you don't want another wine you're not interested in another wine you get 67 emails a day from the 70,000 wineries in the world offering you wine you're not interested I get it but I already have uh eight 800 uh th000 bottles that are tokenized here in the country and those people want to redeem them do you want to get a 15% cut just to receive it to to do the forwarder right and if you want to participate you can buy tokens at a good price and and resell them at the Fiat price that you like right so it's not about eliminating the Fiat uh supply chain it's uh because people will still go into the shop and buy and have no

idea about tokenization and they'll pay for it and or dollars or or Euro right there will be a differentiation between the price they pay in the shop and they what they would find on the exchange yeah could be but guess what wine is also one of those products that you already pay two or three times as much in a restaurant and you know that you're paying more than that and you're like yeah but I want it right now so I don't care right um and if you're a consumer and you read the back label and you scan it and you get your nft and you go what's this all about I want to buy the token well now we've gone direct to the consumer my annual production uh depends on the year weather and what not but

roughly 10 to 15,000 bottles a year so no it's tiny um but basically I could tokenize my entire production since 2018 showing how this works understanding in 2018 we didn't have Unis swab we didn't have metamask that you could send an erc20 token with right we didn't have a whole lot of things so we've gone through this whole Arc of uh discovering this and presenting to it and basically we haven't done any marketing to wineries yet just the ones that have come and said hey we want to do that we see the value in it right it's a very old industry a very traditional industry but like I said about the case in ineson when you walk into a winery and you say

you have a Fortune of wine sitting here it's been sitting here for 100 years but it's basically worthless until you you sell it tokenize it and they go yeah we get that so let's do it so that's why we have to make things simpler more attractive um and whatnot that's that's the real Challenge and making sure that internally in the wineries um they see this as an advantage and and not a threat and some of them won't be interested in it some of them will but there's it there's so many out there that it doesn't matter is there any yeah have this because there is obvious

res well actually that's a really good question um so there's a couple of different aspects here that can be done for example the national wine board in Argentina who I'm just you know every country is a little bit different they have a registry of which wineries actually exist um and the wines that actually exist and they have a online service that can do authentication so basically we went to them and said look we don't want your access to your data we don't want you to do anything for us all we want to do is when a winery and when we have a a a provisioning tool an automated provisioning tool to create your to tokenize your wines all I'm going to do is say okay you're an

Argentine Winery what's your Winery number that will take them to the wine board that will do an a login and password and come back and say yep you authenticated with them so I believe that you're the winery right now give me the an analysis number of the wine and then I look up that in the database and go okay there's 6,700 lers of that particular wine that exists and it's 14.2% alcohol and it's it's a Merlo car Frank and all of that sort of information right so there is a way that we can validate that the wine actually exists and that the winery actually exists uh the next thing is to say well how do I know that they're actually

going to send it to their customers well this isn't a platform that has contact teleph no these are companies that have exist and many times for decades or even centuries and so as soon as they don't fulfill the tokens delivery I mean that that's obviously it's a reputational cost that's very high for them um it would affect the F the cost of the valuation of the token um so that's kind of the guarantee on that point the third aspect which is getting a a bit sci-fi but I was talking to vene about this earlier is working with a a company that's developed a

non-invasive uh spectrometer which basically allows you to identify a liquid in a bottle with a label in a cork right and create a spectrographic profile and so what I want to do with that is to say Winery you're going to tokenize your wine send me 12 bottles we'll scan the 12 bottles and say okay this is a spectrographic profile for this particular wine SL token and if we have a handful of those devices in the world one in Europe one in China where there's big fraud problem with wines um one in the US and one someplace else the the customer that's buying a container half a container pallet of wine right and says is this

really the same wine that they tokenize all they have to do is take any bottle off the pallet stick it in a box put push a button and go the liquid inside is X okay so at least they know that's the same thing that they're getting which today by the way they don't know there's a huge amount of fraud about that about are you actually getting the wine that was written up that that you tasted in the fair that you ordered so if I have a Chinese buyer that comes and we meet in vexo and parus or you know one of these big events they might taste it and say okay that's great I'll buy it how much is it and I'll say seven and four 5 three we negotiate a price between that point and when they actually receive a container or pallet in Shanghai it's

going to be minimum 6 months just because of the complexity of registering labels and shipping all these things that have like again we're not dealing socks and now you're sitting in your office in Shanghai and you open a bottle and you go is that the stuff that Mike made me try there and I liked it and we agreed or did he just ship me something else I have no way of knowing right might have changed in which case I want to know oh did it change because of the product did it change because it's a different product is it just I don't like it today but I liked it but maybe I'll like it next week right yeah did it get hot and it did it get cooked when it was transporting I

mean there's all different kinds of questions that you could you could actually resolve with this right and adding different layers of of complexity to it of how do I trace the actual tokenization with a physical product using a technology like that right um but you know we we can solve so many problems just as it is that um we don't have to go full bore at the the first stage but yeah that's that's the thought let's go drink