In this episode of For Flux Sake, I dig into a problem that hits the minute you move studios (or even just change suppliers): how to convert a glaze when the materials you used in North America don’t exist under the same names in Europe. The big takeaway is that you can’t do a simple “brand swap” and expect the same melt. I walk through how I think about substitutions in terms of what the material is doing in the recipe—fluxing, supplying alumina/silica, or acting as a clay—and why the chemistry and the particle-level reality both matter if you want the glaze to behave the same. We also get into firing accuracy and why I’m such a fan of S-type thermocouples when you care about repeatability. If you’re troubleshooting glazes, the last thing you want is a temperature measurement that drifts or lies to you—because then you’re chasing ghosts in the bucket instead of fixing the real variable. And because it’s For Flux Sake, we answer listener questions too: what to do with a huge amount of casting slip you don’t want to waste, and how to deal with handles that keep popping off. The theme across all of it is the same: understand the mechanism, control the variables, and you’ll stop relying on luck in the kiln.