Published Aug 6. 2022 - 1 year ago
Updated or edited Aug 6. 2022

Skin & Foam Pupa

An extended body caddis pupa tied with latex ribbon - the al dente tagliatelle of fly tying materials.

Nick Thomas

Nymph skin, the latex ribbon that looks like al dente tagliatelle, was popularised by Steve Thornton in the late nineties with his Ammonite Nymph and a variety of caddis pupa patterns. It’s good stuff for tying lots of different flies. The standard method is to taper one end, tie in at the back of a hook, wind forward in half-overlapping turns and voila, you have a segmented body.

Don’t get me wrong, this is all good, but there’s a lot more you can do with some stretchy latex. It can also be used to make very effective and naturalistic detached bodies for tying nymphs or pupae. It’s simple and you get a nicely segmented body of the desired size on a small hook. Very sneaky and stealthy.

If you try and tie a detached nymph skin body directly onto a needle, you’ll find that in can be difficult, if not impossible, to get it off the needle intact when you are done. The stretchy latex wants to grab the needle and pulling can stretch the body out of shape or pull it apart.

The trick is to use a foundation that separates the latex from the needle and easily slides off once the body is completed, hollow braided fly line backing works well for this. You can tie detached bodies using just nymph skin or combine it with other materials like organza ribbon to make some great looking bodies. There’s a section in my book Fly Couture that covers the process in detail.

Making a floating detached body is a simple matter or tying in a strip of foam along the top of the braid and wrapping over it with nymph skin. Stretching the skin at the beginning and end of the body forms a taper at either end.

Materials and tools
Extended body
Materials and tools and the extended body
Nick Thomas
The Skin & Foam Pupa
The Skin & Foam Pupa
Nick Thomas
Skin & Foam Pupa
Pattern type: 
Nick Thomas
Fasna F-120 #14
12/0 brown
Detached body
Virtual Nymph 3mm caddis green nymph skin, 2-3mm foam sheet, hollow braid and marker pen
Thorax cover
3mm brown organza ribbon, foam and marker pen
Squirrel dubbing
Skill level/difficulty: 
  1. Prepare a body as described in the text
  2. Run on the thread on the hook, take down to opposite the point and remove the tag end.
  3. Tie in the body behind the whip finish, wrap forward compressing the foam, lift the front of the body and trim off the waste at an angle.
  4. Tidy up over the cut end and lightly coat the thread wraps with superglue or varnish to lock everything in place.
  5. Tie in a length of 3mm organza, followed by a piece of 4mm wide foam coloured with an olive or brown marker pen.
  6. Dub the thorax, finishing just behind the hook eye.
  7. Fold the foam forward and tie down.
  8. Pull the ribbon over the foam and tie down.
  9. Lift up the foam, smear the thread with varnish and whip finish at the hook eye.
  10. Trim the ribbon close to the thread wraps.
  11. Cut the end of the foam leaving a stub over the eye and colour the cut end.

The finished fly
It floats as it should
The finished fly
Nick Thomas

It’s a versatile pattern that can be fished in lakes or rivers wherever there are caddis pupae, which in practice means pretty much anywhere. I fish it as a single fly on a long leader cast out and allowed to sit or drift. If that doesn’t attract any interest, I’ll pull the fly under and let it float back up to the surface. With a soft squishy body and a small hook takes are usually confident and the fish either hook themselves or hang on long enough for you to set the hook.

Drifting a Skin & Foam Pupa
River trout
The fly in use
Nick Thomas


Bill Ninke's picture

Alternatives to Nymph Skin...

Bodies look great and lots of options for variants. In case you don't have any of the original strips, Hareline now offers a product via US retailers called Kiley's Nymph Skins which seems identical to the original Virtual Nymph product. Or you can cut various industrial protective gloves into thin strips and use as substitutes for the commercial products. A US tier, Safet Nikocevic, has been demonstating how to do this for many years at the International Fly Tying Symposium in New Jersey.


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