"The ‘Mayolica Ceramic’ is a kind of glazed pottery that has been produced since the 16th century in Guatemala, especially in Antigua Guatemala (Santiago de Guatemala by those days), San Miguel Totonicapán, and in Guatemala City (the capital).

This ceramic has a natural white color, and it is manufactured from tin, other colors are added in the second firing (oven bake).

In Santiago de Guatemala (Antigua Guatemala) there were potters who preserved the prehispanic ceramic tradition, however from the seventeenth century began a great boom of local manufacturers that changed the style to make it unique to Guatemala, this trend continues to this day.

One of the characteristics of these art pieces is that they undergo double cooking. During the first one, the ceramic is cooked out at a temperature of approximately 700 degrees Celsius, each piece is given what they call "Bizcochado (biscuited)" a solid surface is to allow each piece once the ambient temperature has been reached, to be submitted to a new process of enamels based on oxides application.

Once each piece is decorated with designs and colors, they do not show the shine and brightness colors you see in the final product at this point yet, but it is until all the pieces are taken to the second cooking at a temperature of 1000º in a brick oven system of rustic technology, but quite effective for the purpose. The yellow color used to be obtained from antimony, the green color from copper oxide, and the black from the iron oxide. The white-cream tone used as a base was obtained from lead.

The genuine Majolica Ceramics from Antigua have four ways of being judged in terms of authenticity and age. The true, fine, older Majolica can be distinguished from the new replicas by their lightness, the thinness of their edges, the beautiful combinations of yellow, cobalt blue, and pale green, exclusively; and finally, the crackled glaze that covers the finesse decoration of Plates, Bowls, Jars and Incensories. Newer versions are very heavy, thick, decorated with darker colors, and most of the time, rough in comparison to the original Majolica."

Mayolica Ceramic from Antigua Guatemala,  Jun 24, 2018 
Spanish School Antigua Guatemala Blog