When put on MOP on china don't paint it on in lines.
If you apply it in straight lines, it will fire in straight lines ...( Actually , the straight lines can be effective on things like snowbanks, etc ... and Kerri Manuel recently had the coolest piece on Facebook qwhere she applied the MOP in deliberate streaks on the rim of a plate.. like rays of the sun ... It was really neat looking).
Swirl the MOP on the china piece with a finger ( could be with finger cot) or q- tip that brings out more of the colors. Do not use a brush. But, you can apply it with a brush in swirls too.. but its the swirly pattern application that will give you the nice broken up pattern that is so pretty with mother of pearl ...
Also, the MOP should be thin, watery. Too thick MOP layer application will blister and burn off .. ( That can be reapplied ). Luster does come off fairly easily .
Why it happened?
Either it was still too wet when you fired it....most lusters you can fire wet and it doesn't hurt but MOP is a temperamental lady. One time you fire her wet and she is fine, the next time and she looks smokey, streaked or opaque.
The other thing is a two prong....you fired too fast and/or you didn't let the fumes/smoke out of the kiln when you fired. The pearlized lusters need to have all the smell fired off before you close the kiln lid and/or peep holes. Good thing to leave the peep holes open through the entire firing.
To fire MOP, put a wee piece of broken china or a tile with a smudge of lbg or blood red on it in with the luster. Both enhances the colors of the pearls. Obviously the gold will because there is gold in the MOP...rainbow and so on. Not certain what is in the blood red....it is suppose to be an iron colour, but it works.
