by Janet Mansfield
Potter/ Publisher of Ceramics: Art and Perception & Ceramics TECHNICAL
Research into glaze and glaze technology is one of the most absorbing activities associated with the art of ceramics. I can remember intense periods of my ceramic research, working with a small test kiln, preparing tests and firing them, opening the kiln the following morning, and repeating the procedure again that day. This activity would go on for many weeks as I built up my understanding of the properties of the materials that were available to me at that time. On one particular occasion, vanadium oxide and its uses in promoting texture in an earthenware glaze was the object of the research; on another it was the increasing percentage of calcium carbonate in a stoneware glaze to simulate a marble-like surface. Such concentration can be rewarding. In this enlightened book by John Hesselberth and Ron Roy, both well known for their knowledgeable and practical approach to ceramic chemistry, we are offered the benefit of their concentrated research into cone 6 glazes, an area of ceramics that is becoming increasingly popular. The principles used in their studies, however, could be applied to glazes at all temperatures. Their stringent criteria set new standards for the whole profession and fully meet their aims in assisting potters make “durable, trouble-free, reliable and reproducible” glazes. Their work is original, honed by experiment and tested thoroughly. Importantly, it is accessible, readable and straightforward. Theirs is a disciplined stance and they urge potters to be equally disciplined, not taking a random approach but to understand each step they take and why they are taking them.
Mastering Cone 6 Glazes is published at a time when there is a need for skills. Potters need to be able to realise their ideas through an understanding of the materials and processes of their art. Potters looking for reliable and stable glazes will find information that is forthright and clear, the reasoning sound and presented in a language that all potters can understand. And there is a challenge too: potters and their suppliers of materials and equipment need to be socially and professionally responsible for their output production. Potters should ensure that their work meets reliable and high standards and suppliers should offer analyses of materials that are correct and repeatable. Safety is an important aspect of making and selling pottery and the authors take this seriously, especially the leaching of toxic materials and the ability of the potters’ wares to resist use and abuse; however, the authors are not alarmist but practical, offering common sense solutions to the storage of materials, the handling of chemicals and the making of work that will stand the test of time.
Dipping into the text of Mastering Glazes I found myself reading on for some time, discovering many useful facts, for example: the crazing, dunting and shivering of glazes is explained clearly; why some pots after use for cooking in the microwave are hotter to the touch than others; and how the presence of one material affects another during firing at certain temperatures. The authors give us a choice of methodology in many instances. They present options for different ways of tackling a problem depending on a potter’s individual preference and interpretation.
This book is designed to be a continuing thesis. The authors welcome readers’ comments and results of further experimentation, and they hope that the text will be augmented regularly so that the knowledge presented will be a vital and worthwhile contribution to the available literature on glaze chemistry in a format that is accessible to all involved in the field of contemporary ceramics. Working with this text will provide the potter with a manual for professional practice and give long-term pleasure and satisfaction.