I make both functional and decorative pieces. Pieces that are Raku or with glass are for decor and not meant to hold water. All other pieces are microwave and dishwasher safe. For use in an oven they need to be put into the oven before heating begins i.e. no preheated ovens. I am happy to answer any questions that you have and am open to creating custom pieces. Please contact me if you have any questions. Thank you!