Hi...FYI.
the first time I used bone china.....luckily a few test beakers in a mini test kiln...I fired the traditional way.
ie. a bisque fire at 1000C.....polished the outside and then glazed the inside .....and fired to a higher temp. 1260-1280C
I found that the clay body and the glaze merged...not a pleasant result IMO.
Thats when i did some research and found that it needed to vitrify before glazing.