Did I read somewhere that undyed yarn is thinner than dyed yarn, all else being equal?
Undyed yarn thinner than dyed yarn
Good question. I don’t know. I do know that with some yarns those dyed darker are thinner because of the dye or dyeing process. It might depend on the fiber(s) in the yarn too. I don’t recall noticeable differences in cotton yarns I’ve used but I’ve not used undyed cotton either.
Can’t answer but I found the opposite to @GrumpyGramma with a bunch of colours I had in the same yarn, yellow was thinner and softer, dark blue thicker and stiffer, mid colours and tones were in the middle.
Acrylic yarns that are ex, black will be thicker than white yarn. The dye will make the yarn thicker and heavier.
You will have less yardage in a black yarn compared to white yarn. The label will have the same yardage listed. Remember the yardage listed on a label is an average over all the skeins in that yarn line.