NOT for use in the microwave. Plus after one year of gentle use the design is bubbling off. I tried to contact the manufacturer but they were dismissive. Point is, these are not for long term use and do not put in microwave as they may explode. Yes, mine had tiny blue flecks all over the microwave, ruining the food and creating a huge mess. This is not Macy's fault. But they should indicate NOT for use in Microwave in the description. Definitely not worth the high cost.