This is really where you need to become a fly tyer! As far as we know, Colin’s flies aren’t commercially available (yet!). The good news is: tying your own flies is actually very easy. You either need to get hold of a basic kit - vice, thread bobbin, fine-pointed scissors, and a pair of hackle pliers - a good beginner’s guide (Try Terry Griffiths and Chris Mann’s Fly Tying for Beginners), and study Textbook tying in Fly Fishing and Fly Tying magazine as it is full of tips. Not being able to find the fly I wanted in the shops is exactly how I got started in this fascinating extension of our fly fishing hobby. Try it - you won’t regret it!
