Because I am so enthusiastic, I am sharing three more pages from my yarn diary. This is yarn that I've spun myself.
These are random yarns that I have spun in the past and don't really have any info on. Hence the title "Random, unknown." In two cases I did have small samples of the roving I spun yarn from.
Everything on the left side of the page was spun with a Louet drop spindle, and the one yarn sample on the right was spun on my Ashford Kiwi spinning wheel.
The pages immediately above and below are examples of the options a person has when they sit down to spin yarn. They are both 50/50 Wool/Soysilk from the same place. They're probably from different dye lots, but the roving they came as was otherwise identical. (Roving is the wool/cotton/other that is ready to be spun into yarn.)
I used a Louet drop spindle for the above sample, and plied it. The plying is two strands wrapped around each other.
Below I (almost certainly) used my Ashford Kiwi spinning wheel, and I did not ply it.
As you can see, the end results are very different even though what I started with was the same.