Xink

I use this product on my furled leaders to help them sink.

It does what it says. My only worry is the rainbow streaks it leaves in the water when you first use it — I worry about the environmental effect of whatever this is made of. But I use it so rarely (I normally fish with beadheads, so it's not needed) I'm not too worried. I use it on the tippet whenever I'm using dry flies to make the tippet disappear in water and not cast shadows that the fish will see.

This does the job just a little on a nymph works without having to add split shot to the leader lets your fly drag more natural on the bottom. After all a Trouts diets is mainly nymphs and other bottom crawlers.

Hides my leader

I tried it on my nymphs but do not see any noticeable difference in their sink rate.

It will sink your leader.