How to Create a Cone 6 Glaze Test Tile System You'll Actually Use
Let's be real. You've got a shoebox full of half-labeled glaze test tiles under your wedging table. Maybe you swore you'd organize them last month. Maybe you told yourself you'd "remember" which was which. You didn't. Nobody does. Here's the thing: glaze testing without a real system is just expensive guessing. You're burning through clay, electricity, and your own patience. But a cone 6 testing setup that actually works? It's not about being the most organized potter in the room. It's about being lazy in the right ways. Set it up once, and the system does the heavy lifting while you get back to throwing.
Pick a Tile Shape and Commit Already
Stop making fancy shapes. Seriously. Curved tiles look cute on Instagram, but they wobble on the shelf and they're a pain to label. Go rectangular. Or square. About two inches by three inches. Thick enough that they don't snap when you look at them wrong. Actually, add a little foot on the back so they stand up on their own. Huge improvement. You want to see the glaze break over an edge, so make sure your tile has a proper vertical face. Flat disks tell you almost nothing about how a glaze behaves on a real pot. Keep it simple. Simple scales.
Your Clay Body Lies to You
You tested that celadon on porcelain and it looked incredible. Then you put it on your usual stoneware body and suddenly it's mustard yellow. What happened? The clay happened. This is the part where most potters get bitter. You have to test your glaze test tiles on the exact clay body you use for your work. Not similar. Not "basically the same." The exact one. Cone 6 testing is already finicky enough without introducing clay variables. If you use three different bodies, guess what? You need three sets of tiles. Brutal, I know. But accurate data is the whole point. Otherwise you're just making pretty little failures.
Mark Them Like Your Sanity Depends on It
Scribbling on the back with a Sharpie after glazing? That ink burns off in the kiln, my friend. Gone. Poof. Now you've got a mystery tile and a headache. Use underglaze pencil on the bisque before you glaze. Or stamp a code into the leather-hard clay. Better yet, both. Keep a physical notebook. Yes, paper. I know you have a phone, but your thumbs aren't faster than a quick sketch and a note. Write down the glaze name, specific gravity, application method, and the date. Date everything. Future you will be grateful. Present you will be annoyed. That's the trade.
Firing Cone 6 Tests Without the Guesswork
Don't sneak your test tiles into the back of a random glaze load and hope for the best. That's not testing. That's gambling. Put them in the same spot every time. Middle shelf. Same stilt. Same orientation. Cone 6 is sensitive to temperature variation, and your kiln almost definitely has hot spots. You need to know if that glaze ran because it's a runner, or because it was three inches from the top element. Also, use actual witness cones. Not just your kiln sitter. Kiln sitters lie. Cones don't. Get a pack of self-supporting cones and place one right next to your test tiles. Then you're actually firing to cone 6, not "sort of cone 6 maybe."
Stop Hoarding Useless Data
After the kiln cools, don't just dump them in a box. Hold each tile up to the light. Feel it. Scratch it with a fork if you're testing durability. Compare it to your notes immediately while the firing is fresh in your head. If a glaze is trash, throw the tile away. Actually throw it away. Hoarding failed tests is emotional clutter. Keep the winners. Photograph the maybes. Write "NO" on the failures and smash them in the reclaim bucket. Brutal? Sure. But glaze organization isn't a sentimental activity. Your pottery test system should be a tool, not a museum. Build it lean. Build it mean. And then get back to work.