In this episode of For Flux Sake, I sit down with Gabriel Kline and Bill Collins to get really specific about what “food safe glaze” actually means—and what it doesn’t. We talk about how the term gets used as a marketing label, when it’s a real materials question, and why “it looks glossy and fine” is not a test. Their new book, Amazing Glaze: Food Safe Recipes, comes out of doing the work: testing dozens of popular cone 6 and cone 10 recipes and then looking at what those results actually tell you about risk. We dig into practical studio realities: what kinds of failures matter most (think durability issues like crazing and surfaces that are more likely to leach), and how you can approach testing in a way that’s grounded in evidence instead of vibes. The big takeaway is that food safety isn’t one magic ingredient or one magic cone—it’s a combination of fit, surface quality, and chemistry, plus verifying with testing rather than assuming. If you’re using “classic” recipes from the internet, this episode is basically a reminder to stop trusting popularity and start trusting data.