Hey guys! I'm looking to make a sink basin for my bathroom in the upcoming months. I want to use Standard Ceramics 266 Dark Brown Clay with a turquoise/seafoam glaze on the interior while leaving the exterior bare. Attached is an idea of what I would like to do. I have never used a dark clay before, so I don't have experience to work off of and can't make test tiles until it is safe to use the studio again. Would coating the inside of the clay with a white underglaze cause the blue glaze to stan