Can you use universal tints on ceramic (clay) paints?

Answer 1

No. Ceramic "paints" are glazes that when fired at above 1000F convert to glass in structure. The universal tints would almost certainly burn out long before then, but you can always ask makers and dealers.

Answer 2

I've been working in ceramics for a long time, and I'm not familiar with using "universal tints." If you're looking for a specific color of glaze, go to your local clay store. You'll be amazed at the varitey of glazes out there. Just be sure to get the right kind of glaze, because they range from low-fire to high-fire. It's important to get the right one.

While you're there, ask about "mason stains," which have a wonderful look all their own.

If you're looking to "paint" your cermics, I'd definitely recommend using underglaze, which has come a long way in the past 25 years. Contemporary underglazes are essentially "true" in color--meaning that the color that you paint onto your bisqueware is the color that you'll get once it's been fired. Once the addition of a clear glaze goes on (after firing the underglazes), the colors pop and become strong and vibrant. I've also had great luck mixing underglaze colors to get a custom color of my choosing.

Now, let's say that you have some bisqued wares that you'd like to paint, but don't want to go through another firing process. In this case, you can use oil paints on your wares, but keep in mind that they won't be food safe at this point. They'll be decorative.

Good luck to you!