The left glaze is "stretched" on the clay so it cracks (it calculates to a high thermal expansion so this is not a surprise). This usually appears after firing but can appear years later. When the lines are close together like this it is more serious. If the effect is intended, it is called "crackle" (but no one would intend this on functional ware). The one on the left calculates much lower - and stays uncrazed indefinitely. Potters, hobbyists and artists invariably bump into this issue whether using commercial glazes or making their own.
"Art language" solutions don't work, at least some technical words are needed to even understand what this simply is: A mismatch in the thermal expansions of glaze and body. Most ceramics expand slightly on heating and contract on cooling. Even though the amount of change is very small, ceramics are brittle so if a glaze is stretched on the ware, it will crack to relieve the stress. Crazing appears when ceramic is cooled and the glaze contracts more than the clay to which it is rigidly attached.
These two glazes look the same, they are both cone 6 satin mattes. On the same porcelain. But the matteness "mechanism" of the one on the left, VC71, is a low Si:Al ratio melted by zinc and sodium. The mechanism of the one on the right, G2934, is high MgO melted by enough boron to also have plenty of SiO2 and Al2O3. The "baggage" of the mechanism on the left is high thermal expansion and crazing (drastically reducing strength and providing a space for a germ zoo). If your ware develops this your customers will bring it back for replacement. No change in firing will fix this, the body and glaze are not expansion compatible. Period.
Ask the right questions to analyse the real cause of glaze crazing. Do not just treat the symptoms, the real cause is thermal expansion mismatch with the body.
Crazed ceramic glazes have a network of cracks. Understanding the causes is the most practical way to solve it. 95% of the time the solution is to adjust the thermal expansion of the glaze.
Glaze chemistry is the study of how the oxide chemistry of glazes relate to the way they fire. It accounts for color, surface, hardness, texture, melting temperature, thermal expansion, etc.