via Amazon:
“Making your own glazes is a fascinating and rewarding process, even more
so when making them from collected ingredients. With little equipment
and following a few basic principles, it is possible to harvest glaze
ingredients from your local environment, such as clay, subsoil, plants
and seashells, to achieve beautiful results in the kiln. Whether you
wish to make an entire glaze using collected materials, or just want to
use them as additions to existing base recipes, Miranda Forrest explains
how to source and prepare natural ingredients, from degraded rocks to
seaweed, as well as giving step-by-step instructions for mixing a glaze,
testing samples, and finally applying glazes and firing your work.
Contributions from contemporary ceramicists who use natural glaze
ingredients give a detailed insight into their working methods and
intriguing results. Encouraging experimentation and a creative approach,
Natural Glazes is a vital resource for anyone wishing to work in a more
natural, sustainable way to develop their unique glaze effects.”

“Miranda Forrest is a working ceramicist and graduate of the BA Honours
degree at the Glasgow School of Art. Based on the beautiful and remote
Outer Hebrides, off the west coast of Scotland, she develops her glazes
from locally collected ingredients and the surrounding environment
inspires her work.”

Buy a copy here.