Allan,

As JeremyH explained it, the monofilament loop makes it easier to tie the pattern without any other tool than your finger.

In fact, the late Ned Long tied a similar pattern, using what he called the pull-over technique. He used stretchy single-strand floss instead of the loop, but he had to use a gallows tool in order to hold the post tight while wrapping hackles around it.

You also suggested that Comparadun or modified Thorax Dun may achieve the same effect, so Hackle Stacker might be redundant.

If you take a look at Ian Moutter's <Tying Flies the Paraloop Way>, you can realize that Hackle Stacker or Paraloop flies can achieve certain effects that Comparadun, Parachute, or Thorax Dun cannot.

For example, instead of tightly tying down the hackled post at the eye of the hook, you can tie it very loosely to make it form an arc over the thorax area, leaving some space between it and the thorax. Then, the profile of the pattern in the surface film will be different.

Here below are some examples from Hans Weilenmann's website of what I am talking about. As you may notice it from the photos, Hackle Stacker floats in the surface film, tilting upward at an angle by you forming an arc and leaving some space between the hackled monofilament post and the dubbed thorax. If you leave no space and tie the post down tight, then, it will float horizontally in the surface film.





In addition to the profile in the surface film, you can achieve more realistc footprint as JeremyH mentioned. Ian Moutter's book shows a photo of the footprint of Paraloop flies when viewed from trout's perspective.

You might still say that Comparadun, Parachute, or Thorax Dun can achieve a similar profile in the water. But, I would say that even for that case, Hackle Stacker makes things easier in more systemic ways although I think Hackle Stacker is unique.

Try it, and you will like it.



[This message has been edited by adso4 (edited 27 February 2006).]