I've been making terra-cotta pots for my plants. The pots i paint with mason stains, then fire. I fire to cones between 03 and 5. What i'm finding is that once these pots have been fired, many of the colors i've applied tend to rub off. I dont want to use an over glaze, its very important to me that the surface remain flat/matt free of sealants. Other times the mason stains turn to dark olive greens and browns and yellows, like rotten bruises. (this is after they've come in contact with water). Has anyone worked with this, come across these problems, or have suggestions on proper mason stain mixtures?
I'm typically measuring by eye, water, pigment, some flint, some light bodied clays and some of the base clay used for the pot thats being painted. (i have an ingredients list at the studio if thats needed)
i've attached 2 pictures, one is of a pot fresh out of the kiln, the other is one thats gotten wet a few times.
what are your thoughts!!!???