For those of you who use tippet rings to connect your tippet to your leader, does the tippet need to be very close in diameter to the leader or can it be a few “X’s” apart? I mean, if you are using a 7X tippet does the leader need to be a 6X or at most a 5X to achieve a good presentation…or can you go up to a 3X or 4X leader and still have it perform OK?
Joe
I don’t know that the two leader segments need to be closely matched. I have been using 9 foot 3x leaders , tying a tippet ring to the end and then most times tying 4lb test fluorocarbon to the opposite side of the ring. it doesn’t seem to give me any problems, but maynot work for all
The maximum step down is proportional to the linear mass density change.
I can go through the math but the short cut is to multiple the diameter of the larger section by 2 and then divide that by 3 to get the smallest diameter tippet you can tie on. For example, lets say the leader ends in a 2X section which is a diameter of .009". 2X9=18, 18/3=6, .006" or 5X is the smallest tippet you can tie onto the 2X.
You will read that you should not change more than .002" (2X sizes) at any leader know but that is pure garbage. The maximum change is related to the mass and stiffness of the thicker turning over the thinner section and a fixed “2X” difference is a different change in mass when 1X is tied to 3X (.002/.01= 20% change) vs a 5X tied to a 7X (.002/.006=33% change). So the relative change in diameter from 5X to 7X is 1.66 times that from 1X to 3X.
A fixed 2X (.002") change in diameter leads to different relative changes in mass a the knot.
The maximum change is a 1/3 change in diameter which the multiply by 2 and divide by 3 gives you. A 1/3 change in diameter is a 50% change in linear mass density. You can change up to this amount at the knot and the energy transfer will occure smoothly. Of course you can always change less than that amount.
Can be as close or as far as apart in size as you like. Just depends on how important that last bit of taper is to you to have your flies roll over. Considering that they are mostly used for nymphing, proportion does not really matter that much. When they are used in furled leaders with dry flies, I assume it is pretty much the same because the mass of the furled leader does all the work.
I use Uni-thread furled leaders with a tippet ring, and then Fluorocarbon tippet. And where I always stepped my nylon leaders and avoided more than 2 sizes of step down with them because of hinging, the furled leaders are not quite the same.
I use a 5’5" furled leader tied for 4-6wt lines, and I can tie on 6 foot of anything from 3-7x tippet and it rolls over just fine. As long as I am staying close in matching my fly to my tippet size. 
the only time I have a problem is when I’m throwing 3X and a lot of weight. But that’s to be expected.