To all intents this is a good solvent-based varnish. The consistency is excellent. Nice and runny, it saturates into thread well. I could find no bubbles and absolutely no tendency to form ‘strings’ as I pulled a needle away from the head. It took a couple of coats to finish a head and the result was smooth and reasonably glossy. The brush is, as one should expect, more suitable for fingernails than flies. Cut down the bristle bunch to about one third of the size and it can be used on large flies.

Unlike most fly-tying varnishes (in fact, unlike any as far as I know) UV Fluo varnish reflects UV. Exactly why that might be of interest to anglers is not as obvious as it may seem. According to most of the research I’ve read (some but not a lot) trout do not see UV light. Their spectrum of light in which they see is not identical to ours but is similar. So a varnish which emits UV, when stimulated by UV is not that obviously exciting. Ah then! Having puzzled a little about that, apply this varnish to the head of a fly tied with a fluorescent thread, one which is unnaturally bright and vivid – because UV reaching the pigment in the thread causes that pigment to emit visible light – and you have a reason why this may be useful. Treat the hot-spot heads of flies tied with fluo thread with this varnish and they may be just a little more vivid, just a little more attention grabbing.