I hesitate to write an article on glaze formulation when there is so much on the Internet. Still, there are a few generalities that might be useful.

Some years ago I categorized many glaze formulations according to firing temperature and surface finish. I did this for lead and non-lead glazes both glossy and matt. I was amazed how easy it was to correlate composition with firing temperature (pyrometric cone or Buller ring).

You might run the same type of exercise if you are looking at many glaze compositions trying to come up with just one. You can start your formulation activities using the averages of the ranges of composition for each oxide addition for the temperature range you are shooting for.

The properties of a glaze can be calculated from the composition. For example, you can calculate the thermal expansion coefficient. In my experience, the calculation do not match the measured properties of the final glaze. However, relative calculations are usually true. You might not calculate the exact measured value but you will know that Glaze A will have a higher expansion and lower viscosity than Glaze B.

My associates formulated hundreds of glazes over the years for earthenware and fine china. Much of this work was done in a joint effort with frit suppliers as existing frits don