This is Plainsman Buffstone with G2931L glaze fired at cone 06. A hotter bisque not only produces a stronger body but also eliminates crazing (these specimens where glaze-fired one month ago). Firing the bisque just one cone hotter has transformed the ceramic into a denser matrix having a higher thermal expansion. That has the power to put the squeeze on the glaze, preventing it from crazing. Hotter bisque temperatures can be problematic as they reduce bisque absorbency (thus lengthening dip and drying time for the glaze slurry). But for low temperature hobby ware this is not as much of a problem since glazes are gummed and dry slowly anyway. They are multi-coated for this reason (these were applied in two coats).
What is the difference between earthenware and a regular stoneware body? Earthenwares lack the glass development to fill voids and glue particles.