For those members just starting out and trying to understand the melting points of Opaque and Transparent enamels, also labeled, soft, medium and hard - please refer to Thompsons Fusion Chart which is enclosed in their catalogues.

I have marked the columns in a more understandable text so I would not forget the difference between Fusion Flow and Softening Pt. The Fusion flow number tells you exactly what type of enamel you have, hard, medium or soft flowing.

The first column on the left lists your enamel colors by number - #1000 numbers are Opaques - and the #2000 numbers are the Transparents -

The second column "Fusion Flow" means "HOW RUNNY" the enamel is when fired. Its viscosity. The relative rate or speed that the enamel will flow at the stated temperature.  The  smaller the number the less runny -  and is hard firing - and needs a longer time in the kiln. The  higher the number means the enamel is soft and will go quickly.

From 1006-1060 is White opaques

From 2001 - 2061 is Clear Fluxes

2010 flux - is soft and most used

2020 & 2030 flux are medium

2040 is a Hard Flux

The Third column Expansion - Means how the enamel heats & cools.

The Fourth column "Diatometric Softening Pt. is "the "MELTING Pt." of the enamel onto the metal in Celsius or Fahrenheit.

As a general rule of thumb:  ENAMEL with a HIGH RATE OF FLOW and Low Softening Pt.

should be applied OVER an Enamel with a LOW RATE OF FLOW and High Point of Softening.

A Soft firing enamel should always go over a Hard firing enamel.