By John Thatch With the rapid growth of the adult coloring book industry in late 2014. More and more people have discovered the wonderful world of adult coloring books to gift or buy themselves. I have spent hours examining different coloring books and doing the legwork to compile this list of the best adult coloring books sorted by category, quality and difficulty. I hope this list will help you find what you are looking for.The benefits of adult coloring books?Coloring books are widely used for various health related causes. Coloring books have been used to explain difficult traumas to children, rehabilitation of body coordination, relaxing of adult professionals, and communicating with autistic children. Which coloring pencils to use with your adult coloring book?This depends primarily on 2 factors such as:Do you want to frame and hang up your art?How detailed is your coloring book? As you browse below you will notice that some adult coloring books are much more intricate and complex.If the answer is yes to both of these then I suggest you check out our coloring pencil guide. It might seem a bit overkill to tell you that there is an actual choice and difference in choosing the best colored pencils for this relaxing activity. But without going too much into detail if you want your colored page to last a very long time( like actual fine art). Then you will want pencils that are highly lightfast ( resistant to light decay). If your coloring book is detailed and complex with a lot of fine nooks and crannies that you need to fill in then you will want/prefer a pencil with a harder core that will stay sharper longer than most expensive coloring pencils that tend to be soft because that's what artists usually prefer. Ideally you'd want a mix of soft and hard pencils. This is a site for artists after all.1. Johanna Basford The famous Johanna Basford is known because she's the poster artist for adult coloring books which became incredibly viral during the christmas of 2015. This Boredpanda article suggests she has sold more than a million copies. She's incredibly dedicated to her craft. Even saying that should she be dissatisfied or find a minor mistake in her work she would start the entire page again. All of her work is handmade. Now if that's not true dedication to the craft, what is?2. Adams Media Back in the 18th and 19th century scientists thought it to be important to capture nature in it's true form. These pictures are from those botanical and scientific prints made 200 years ago. Isn't that amazing?You can see it in the fine detail and realistic color blend how much love and care has been put into making these. Incredible plants and creatures from ocean depths and land. Adam's media is known to deliver quality work but you'll find 60 beautiful illustrations aswell to keep you busy. So get your colored pencils because soon a royal octopus might also hang on your wall.3. Kerby Rosanes Now this is what I call photorealism Illustrator Kerby Rosanes from the Philippines has a talent for capturing the indricate facial expressions of animals."Animorphia" is a combination of love for the craft but also vast experience. Supposedly Kerby draws from his own life and as a result we have something that resonates with people while still keeping a professional edge that's unwordly. His work is care free almost childlike but superbly detailed. I would suggest this for people looking for a challenge. 4. Millie Marotta The last but not in any shape or form least Millie Marotta's Animal Kingdom is another fine example of nature art.If you like symmetry, nature and have zen like patience for something so intricate you'll find nothing better than the coloring book by Millie. She alongside Johanna Basford was one of the first to start the craze.Much like Kerby she draws inspiration from her surroundings and experiences in life.5. Shan Jiang Shan Jiang is an amazing artist. His work seems surreal since it tip toes in both realism and fantasy. As you might've guessed the coloring book is about a riderless bicycle around the world accompanied by a creature in each picture. I really love this coloring book because of the mix of asian cartoons and western street art is so delicately familiar and yet out of reach. Another great gift book for friends of the outdoors or modern art. 6. Lizzie Mary CullenA christmas special a fitting gift for the holidays. Lizzie Mary Cullen is a classic illustrator who has combined classic adult coloring books with this oldie but a goodie theme. It features everything Xmas from America to Australia. Santa, elves, drums, tree decorations, sugar canes everything and anything you can imagine and loved from your childhood you will find in this article.7. Alisa Burke Featuring a women is just smart marketing by Alisa Burke. I wonder if it was intentional? Oh but the art is beatiful on it's own. Check it out!Feminine Wild - Alisa Burke8. Yellow Bird Project Want to feel good about buying a coloring book and not even drawing? Get this Indie Rock coloring book because all of the royalties go to charity. The Yellow Bird Project is a great cause supported by great indie artists. 9. Peter DeligdischColor me crazy is truly unique with more lines and drawings than you can fathom or possibly count. It leaves room for drawing however you wish over or inside the lines. A big book. I give up. I really don't know how to write more about this. Lazy marketer. Mindfulness Coloring Books10. Emma Farrarons What do you get if you combine an art therapist and an artist? A noteworthy adult coloring book for mindfulness. Color Me Calm is truly zen. You can already feel it from just looking at the cover. The book by therapist Lacy Mucklow and Artist Angela Porter will keep you distracted and calm for months. This book features different themes and topics so you'll get to choose from different subjects.11. Jim Gogarty A mandala is a sacred symbol in Indian religions, it's purpose is to represent the universe. In the House of Cards we saw monks construct one by hand with fine sand and days of work. The same principles, the same style has been brought into this coloring book. If you're looking for some inner calm buy this artbook and get to work. You'll find enough work in this book to last you months.Funny Coloring Books 12. Mike Coley Yep, you guessed it. This artbook is about Bill Murray. Love him or hate him this artbook is just proof of Murray being a national treasure. You just know you've made it when there's a coloring book themed after you. This coloring book is not very strict just like the character you can just go nuts and color over the lines. 13. Theo Nicole Lorenz Theo Nicole Lorenz just understands millenials. This coloring book is the epitome of the internet age. Unicorns rule. In this coloring book you'll find 18 pictures of unicorns misbehaving like they should.14. Richard Merritt Blue is my favorite color. Now mix it with flight and you have one of my favorite coloring book covers. The Aviary explores the world of birds . Since I was a kid and started sketching I've obsessed with drawing critters in detail. I could spend hours on a tuft of hair or feather. Many different birds in insane detail that will keep you busy for hours. So if you're like me and have an appreciation for birds check out The Aviary. Another cool feature of this coloring book is that you can rip out the pages with ease and gift them or hang them on a wall as stand alone art.