>>11310971
>I'm sure it is within a normal deviation
I realise this is probably an issue, so I haven't started yet and am just measuring for a few days to get an accurate starting point. It's especially important since I'm going to be testing both legs to compare base mixtures. Before further tests.

>using measuring tape isn't that easy
Well I'm glad it's not just me. That's why I made a plank to measure along, cutting up a few measuring tapes and nailing them along where I'll put a pen to mark the front of the thigh
https://files.catbox.moe/fs3v7g.jpg
I realise the hole is tedious to use though, so I'll want to make some sort of jig to mark it in place

>pull it just a little too hard
I pull it as tight as possible and then slowly release until it's held in place by just the weight of my fingers. It does take a couple tries since you also have ti make sure you've lined it up and it didn't shift up or down from the line. That's why I found against the floor to be the easiest measuring place.

There are a lot of factors that could be affecting the difference. The aforementioned difference in derma roller and the main one which is considerably different body composition. The fact I way over 2x your weight probably isn't insignificant.
I do also wonder about potentially different suppliers and maybe even different diets since I do drink a lot of water and track my micronutrients fairly closely