Bisque Underglaze Twice??

[grendel]

I recently read that an artist fired underglaze twice to 'make it permanent'.  Isn't underglaze permanent anyway? Confused.

[Bill Kielb]

Some folks use underglaze on greenware, some folks underglaze on bisque. Some folks underglaze one coat on bisque, bisque fire again and add more underglaze to their design without fear of disturbing their first coat.  So on greenware, I guess it’s fired only once if it’s fired from green to glaze as a single fire. If it’s applied over bisque then it still only goes through a single firing - the glaze firing. If an extra bisque firing is done for multiple coats, then the first coat of underglaze is fired more than once counting the glaze firing.

So the extra firing allows one to decorate over an already underglaze decorated design.

Edited May 18 by Bill Kielb

[Callie Beller Diesel]

I’d have to see the description this artist made of their process to be more specific. The only thing I’d add to Bill’s explanation is that someone may have just used bad syntax to describe their process. Or maybe they’re in a group studio and they’re at the mercy of a dictated method of firing. 

[Rae Reich]

Could it be that the artist was referring to separate firings for underglaze and glaze?

[Babs]

On 5/19/2024 at 4:29 AM, grendel said:

I recently read that an artist fired underglaze twice to 'make it permanent'.  Isn't underglaze permanent anyway? Confused.

The word permanent may be a misuse of that word.

The only reason I can see for firing underglaze prior to glazing, or  applying more underglaze is so it isnt smudged by the potter in handling the piece incorrectly, or applying glaze. Not sure if the word sinter is the right one but , this sinters the underglaze and will avoid smudging unless the underglaze is applied really thickly, some of the dark colours may still smudge, I have found.