Rather spontaneously, (and entirely forgetting that I'd wanted to buy a second batch of Stroll roving before dying it so that I could have more yarn in the end), I decided to play with some pink.
I prepared the roving by soaking it in a vinegar solution (I can't remember how much vinegar, but a moderate amount, anyhow).
Next, I prepared the dye by adding a good dollop to hot water and very slowly adding a little bit of vinegar (the second time. The first time I sorted out that I wasn't adding it quite slowly enough, as the dye broke, and that wasn't the plan).
I added the dye to a series of bowls as evenly as I could. I wanted pink and white stripes, so I left a fair bit of space in-between.
After the dye was soaked up, I wrapped the whole thing in plastic wrap (which I try not to use very often otherwise), put it in a crock-pot, and heated it in the microwave.
I rinsed it, and was pleased that there was little to no bleeding, and that the colours had mostly stayed put in their stripes, though I didn't mind the bit of mottling here and there.
I took my time spinning it up; it was entertaining contrasting it with the more rustic wools I was spinning at the same time on the other spindle, as this stuff feels much like spinning a rather springy bit of fluffy cloud.
Chain-plied and after a bath, here is the resulting yarn! There will be stripes in whatever on earth I make with this. It's all very satisfying, and also feels nice to tie something up before everything gets crazy-busy.