I found where Copic uses alcohol based ink which is what's needed for Coro's technique. It's not necessarily a better deal than the Tria but if you're just wanting to try it out without a big financial commitment you can buy 18ml refills for 4.46. You can only buy 40ml Tria ink and it's 8.75. So it's not as good a deal but it is if you're not wanting that much. Here's the link This is a limiMister Art . This is a limited select though. You can get a bigger selection but more expensive at Blueline Pro . Here's another ink I found that I believe is alcohol based ink specifically for graffers, this site is in another language though so maybe an overseas friend could translate. On the Run Looks to be very cheap but is only three colors.