These are small glaze cracks, which are characteristic for many of our series. These small hairline cracks are caused by the reaction of two glazes, which are also responsible for the unique color gradients, but do not represent a quality defect and do not affect you in the everyday use of our dishes. These occur sometimes more and sometimes less depending on the amount of glazes applied by hand and can change over time due to temperature fluctuations. These glazes are also referred to as "craquelure". https://de.wikipedia.org/wiki/Krakelee