I have been using Soldate 60, fired to cone 6. I haven't had any issues, but recently was wondering if maybe I should switch to something similar, but made for cone 6. I called Laguna and they didn't know what would happen with firing it at cone 6. Has anyone had an actual problem with Soldate 60 fired mid-range? My glazes are all good, I haven't had any unusual issues with my work. I find Soldate 60 to be a great all-around clay to work with and it is inexpensive.