Popularised by top carper Jon McAllister, who first used it in 1990 having been shown the premise by Dave Ball, the multi rig (or 'Jonny Mac' rig) is a hugely popular pop-up setup. It can be tied quickly and, unlike any other carp rig, allows the angler to change their hook almost instantly. Variations on the basic rig include adding shrink tubing or silicone to the hook eye.
Step-by-step guide to tying the multi rig
1) Take a length of coated braid and double it over. The multi rig can be tied with a variety of materials, but stiff or semi-stiff coated braids are best suited.
2) Form a figure-of-eight loop knot. The size of the loop will determine the 'height' of your pop-up hookbait and must be able to be pulled over your chosen hook. A loop of 1.5-2ins is a good starting point if you are unsure. When tightening the knot, make sure the loop does not twist or kink.
4) Hoop the loop over the point of your hook and into position like this. Your choice of hook can be quickly changed if it blunts or you want to alter the size.
5) The next, and crucial, step is to create a hinge just below the knot. Do this by stripping a small section of coating from the braid with your nails or a stripping tool.
6) The final step is to counterbalance the buoyancy of the pop-up. You can mould putty around the knot, or place a splitshot or similar on the stripped section of braid.
OPTIONAL) A piece of shrink tubing or silicone over slid over the eye of the hook will stop the looped 'D' section from slipping and can aid hooking mechanics, though it makes changing hooks harder.