Sorry I didn't get back sooner. I would hate to steer someone wrong, but I have used it to seal candy tin seams and clay pots for candles and it was fine. I am not selling though so you probably should research it. I made the cutest little clay pots once and sealed the bottom with a penny and sealed the porous clay with modge podge and painted the outside and saucer with acrylics. I was new and read it somewhere so I tried it and it was really cute. I only made few though. Sorry I couldn't be more help. Trying to research this and think it might be safer on the out side of the jar....:embarasse