Message #13663

[rpfstoneman]

All,

I’m still trying to answer these questions myself.  When looking at this issue you need to make the distinction between 1) the body (hard or soft paste porcelain, i.e., the clay mixture of the body as Joey points outs), 2) the over glaze mixture, and 3) how the over glaze reacts to with the body when fired.  Yes, my understanding is hard past porcelain (the unfired clay base) is decorated, glazed, and then fired once.  Additional over glazing decorating would require one or more additional firings (ex., over glaze iron red enamel that is then gilded with gold would require two additional firings which the same process as I remember my mother doing in her years of ceramics).  All these firings at different temperatures as Giovanni points out.

Now, to the question of soft paste.  Is it fired once or twice in the initial forming of the glazed item?  I don’t know for sure.  Will have to get back to my notes and reference sources unless someone else here knows.  The answer could be both process would work depending on the glaze mixture and how it reacts with the unfired or fire body. 

Charll