The 66 Simple Collection delivers 66 original illustrations, featuring inverse-mirrored images on opposite page sides, each a perfect negative of the other. Every line, shape, and detail on the front is mirrored on the back, each page a balance of perfect symmetry. Because of this negative symmetry, both back and front can be colored without bleed-through color contamination, enabling the exploration of contrasting color schemes or similar tones across both sides. 66 Simple Celtic Mandalas & Designs introduces this innovative schema through the meditative beauty of classic Celtic motifs , including the Trinity Knot, Celtic Cross, Tree of Life, Quaternary Knot, Triskelion, Spiral Knot, Triquetra, Solomon Knot, and many more. With 132 colorable pages in each volume, 66 Simple delivers unmatched value in a compact, 8.5in x 8.5in coloring book. A perfect gift for the young and old artists in your life, for that one special someone who just needs to chill out, and for yourself. When did you last take the time to enjoy something simple and pure? Coloring has consistently been demonstrated to reduce stress, increase focus, and have a positive effect on overall mental well-being. Freedom of expression within well-defined yet fluid structures is an incredibly liberating and cathartic experience. Find out for yourself in our expanding catalog of coloring books at Mindful Coloring Co. Appropriate for ink, pencil, crayon, and marker.