My students pots which have a 'enclosed' shape after bisque firing are white inside rather than its usual and outer pink shade. The pots are made from school buff clay and were fired to 1000 degrees.
The firing was reasonably compact, one source has said that the differing colours could have been caused by poor circulation in the kiln caused by overcrowding.
Could there be any other reason for the different bisque colours? and will it affect the pots ability to hold glaze?