I have an issue with white ceramic earrings that I am trying to solve. I make and sell white disc form earrings that have a glazed front but an unglazed back surface. I recently saw a couple of customers both who had found that over time their earrings had yellowed. Both customers are friends and have worn their earrings almost daily for a year or so. From what I could tell it seems that perhaps hair oil and products had seeped through the unglazed back of the clay and 'soaked' the whole earring so that the front has also become yellowed.
Has anyone got any ideas of how I could prevent this, save from glazing both sides which would really complicate the way I currently fire them....could you recommend a suitable sealant? Perhaps a metal lacquer that I could apply afterwards?
I would appreciate any of your ideas or experience!