...merely a tool, which definitley involves work on behalf of the reader. There are no pictures or test tiles to rely on; you have to try them yourself... a refreshing change from the results usually included in glaze books because you have to experiment and come up with your own results. I used the 1970's edition of this book as an undergraduate, which included the original recipes - not revised to exclude toxins - and while the revised edition is informative, it lacks the conversions for the "toxic" ingredients which many of us still use for the stunning results they provide. As a result some of the best recipes have been excluded from the new edition, and unfortunatley, the replacements and substitutions produce nowhere near the results gained from earlier editions. Still a good tool for the potter who enjoys glaze experimentation, but if you can score a copy of an unrevised edition(there are two- and they are out of print), you are sure to be pleased!