Mechanical lifting advantage: Jute or Hemp?

(posted in the “shibari” group on Fetlife 8/10/2018)

When lifting either partial or full body weight, using a ring, and an Austrailian bight, I have never had difficulty achieving reasonable lift without using carabiners or pulleys. I had been using jute, which has been well treated and used over the past year or so, but not at all worn out.

Recently, I have had experiences where I was pulling up a hip harness, after a TK was locked off, and haven’t been able to achieve lift. Things just seemed stuck. I carefully examined the ropes I was pulling up on, and the rope that went down to the Y-attachment to the hip harness, making sure it was not jammed in any way, and everything seemed good, but I wasn’t getting the “mechanical advantage” of lift.

The weight/size of my bottoms has been not a factor in this difficulty. I am a fairly strong and fit person.

Then, it occurred to me that I had switched from jute to hemp for my uplines, reasoning that hemp is higher rated for strength. That switch was where this problem first began.

Is this a thing? Hemp is more “floppy” and “frictiony”. Maybe the jute, which is stiffer, lends itself to achieving this mechanical advantage.

(Note that I never, ever, ever rely on a single line to lift a tying partner!)

I am really loth to use mechanical devices, like carabiners or pulleys near the body, and stick to strictly natural Japanese technique. The downside of using these devices is obvious from a safety standpoint – they release suddenly and catastrophically. (Of course, I know it’s always up to me to keep the “brakes” on).

I frequently tie on a single right, using 3 – 4 uplines. I want to be able to easily raise/lower and then raise again any part of the body, or the entire body, confidently and smoothly, so the experience of my partner is serene and fulfilling.

Should I go back to jute for uplines?

Has anyone else had difficulty with hemp achieving mechanical lifting advantage or should I look somewhere else for the problem?