Kurt, I’ve used Parafilm quite a lot. It makes one of the quickest (and beautifully translucent) midge and caddis larvae ties out there –although I’ve beaten my own speed records with other materials. It’s pretty durable too, when cold –as in trout water. It’s a translucent but slightly cloudy fleshy white in color that colors up with markers really well –allowing you to leave pale bellies. Because of its “lack of puffiness” it requires some design adjustments to get some of them to drift oriented upright, as mentioned. Check em in the bathtub before you take em to the stream.
The 2nd pattern was introduced to me by Joe Cambridge as the “Kimball’s Emerger“, although the Kimball’s is actually tied with a loose wingcase to be fished in the surface film. I first used the present nymph version on the Delaware in tandem with the dry for very touchy browns (and a couple brookies! –not the usual thing on the Big-D) that were taking 5 Baetid nymphs to every dun. The nymph on a short dropper allowed me to catch those selective and wary browns. Takes were so subtle in that calm water that they registered as tension in the dropper line, or simply by water movement; It was easy to miss them. I kept shortening my dropper when I realized just how light takers they were. The fly has worked in many circumstances since, but detection is critical and this requires deft control of the rig.
Do try the dropper rig. Following are some important details so you aren’t frustrated with the learning curve in getting the most out of the rig. If you are willing to read, I'm willing to write. :)
First, I edited the OP a bit, realizing I wrote that I use Comparadun patterns where I meant to say Parachute patterns, which support the dropper better. The tail is important in that it is what supports the dropper first. If it sinks, your dry is severely compromised and won’t remain an indicator either, for long. Grease that tail and the first couple inches of dropper, which I then snug right up high near the tail. I’m going to experiment with a combo tail like Matt uses on his Comparaduns –using well splayed fibettes over antron –likely an improvement. There is also a guy who ties a loop of fine gel-spun polyester (poly braid line), which floats, into his indicator flies coming directly out the back end which add to the tail buoyancy, which he then loops or ties on the dropper. Nifty idea I’ve yet to try.
This rig is for targeting specific drift lanes (laminar flow) as turbulence (much slack in the dropper) will cause a disconnect between the dry and nymph, thwarting strike detection. The idea is to keep the dropper straight enough between dry and nymph that you can detect takes. So, first, a short fine dropper is important. The rig fishes better as the dropper gets wet, when it will sink out of the sticky surface film more readily, but again, grease the first couple inches to help the fly stay up. Fluorocarbon I felt sunk the tail of the dry fly too readily.
The proper cast places both flies in the exact same lane, and in line with each other; the nymph following right behind the dry. Ideally you want a bit of slack in the dropper so the surface film doesn't capture and skate it around. One way to do this is to get the nymph to splash down first –or at least not have the dry land first with the dropper landing somewhat taut where the surface film will likely capture it. This is easiest with a little weight on the dropper. Keeping the nymph wet helps too. Avoid throwing uncontrolled curves; If you are throwing curves – not controlling the nymph – you will not be catching fish on it and might as well just fish the dry alone. Standing directly below the feeding lane is the easiest position, and using the old “book under the arm” style helps keep the line leader and dropper staying in line.
If, on the drift, turbulence is creating too much slack in the dropper for detection, I add a tiny bit of tungsten putty or the tiniest of shot –which cures a lot of detection ills. I like the putty now bc it is so easy to work with: no dropping tiny shot with cold fingers, I can easily remove it or add more, and it can’t damage the fine dropper. With a heavy hook on the nymph you may not need to add weight to the dropper; See what the current allows. If good fish are taking duns real well, I may forgo the nymph. But a good proportion of the time, especially during sparser emergences, the better fish are more susceptible to the nymph than the dry, so it’s worth getting to know how to do it.
I mentioned this rig as a prospecting rig bc Baetids are so common, but it is not a general prospecting rig when factoring in the range of current types streams dish out. It helps to know where it can be put to good use. It is delicate enough that it requires smooth flow and really shines on calm water. If there is much turbulence it’s best to go up in dry fly size (often beyond Baetis size) for the buoyancy, so you can add weight to the dropper.
Still more turbulence? In my mind the dry/dropper deal hits diminished returns quickly. “Dead-drift” below the surface is not accomplished (in anything other than laminar flow) the same way it is with a dry fly, because strike detection is destroyed when you introduce the slack you need to get a natural drift with a dry. Instead, a nymph must be lead (pulled), as you mention, one way or another, even with an indicator (except possibly on really laminar flow, both horizontally across the lane and vertically, which is rarely offered by streams, (but more apt to be found in the more stable lowland rivers). Such spots DO exist on smaller waters, and recognizing laminar flow is key to catching. Sometimes they are rather large and long –“soft spots” I call them (coined by Tom Rosenbauer) - but most are discrete. Trout know them, as this is where they drift feed.
It is possible to attack the more turbulent (and deeper) spots by going up in shot weight, which then requires more buoyancy in the indicator, and a larger outfit to handle it. The difference does not appear to be linear, but exponential (to some unknown factor). I can indicator fish pretty “heavy” water when steelheading, but by then I’ve gone up to a 9wt outfit! For trout fishing, well before I need to break out the 9wt, I’ve dropped the indicators altogether, and fish heavier waters by feel.