Each book references one of the four classical elements: earth, water, air and fire.

Some 85% of the company's products carry FSC Chain of Custody (Mixed Sources) certification.

The remaining 15% is FSC-Controlled Wood, which is made from cellulose that, despite not having FSC Chain of Custody certification, complies with its basic principles.

The products are designed and illustrated by Design LSC and printed by Lancashire-based NB Colour.