You might think that painting orchids was a subject too specialised to be of general interest. They are, however, one of the most varied flower types and, of course, some examples are highly prized by collectors. Not all types are exotic, though, and there's a good chance you have some in your own garden or at least locally.I realise I'm probably going to have to work quite hard to convince you that a book about a single flower type is one you'll want to read, but Vivienne Cawson helpfully comes to my aid. She is not, she explains in her introduction, a flower painter by nature: "My heart would sink when my tutor appeared laden with flowers of suggested that we go to the Botanical Gardens." Her background is textile design and geometric shapes, which means she brings a fresh eye to the subject. It gets more interesting when she mentions her influences, including Shirley Trevena and Elizabeth Blackadder, as well as developing interest in gardening. Suddenly, she has the materials to work with.So, what we have here is a new approach to the subject that provides endless opportunities. The result is a book which is endlessly fascinating and which tells you far more about flower painting in general than you'd ever expect. Although this book is backed by Kew, it is by no means a botanical guide - which is something of a surprise in itself. Rather it's about colours and shapes - in simple terms, it's about the art, not the flowers. Now do you see why I'm getting a bit excited?In practical terms, the introductory sections contain succinct yet thorough information on colour, tonal values, positive and negative space, shape, brushwork and a whole lot more. It's all thoroughly practical and there are plenty of examples and exercises to get stuck into. It's actually quite easy to forget you're dealing with orchids specifically as you learn about stems, leaves and petals - even roots - and how everything complements something else. It's all rather good fun, which is perhaps the most important thing. It all comes together in just three full projects, which should be enough unless you're really into orchids. The main thing is that you'll have had a thoroughly good time learning about colours, shapes, contrast and harmony - a well-tended garden, in fact.