Testing My Bottles!
Porcelain clay, when it's fired at the right "curing" temperature (this is usually around 1280 degrees Celcius), gets vitrified and watertight, even without any glaze... it's non porous, and if a fired porcelain piece is boiled in a pan of water, it only absorbs 1% of its weight!
Porcelain vases, hold water better though, if they are glazed. The glaze makes the piece completely watertight, unless there are cracks or faults in the glaze after its been fired.
I like my vases completely
