I posted what follows (in italics) on another board on February 2, 2013 (almost four years ago). At the time I was still refining my first handle-design, had only purchased two M&Fs directly from Lee, and had not yet conceived the idea of approaching him about a group buy on B&B (that came a couple weeks later).
Knots don't start out being Rooney, or M&F, or Simpson, or Plisson. They start out as badger hair. Hair from different badgers gets sorted into lots, or at least that's what I assume. Buyer's negotiate to purchase lots. Sometimes those buyer's may be individual brush makers who either keep the lot for exclusive use in making their own brushes, or part some of it off to others. If they sell some of, there might be no real difference between what they keep and what they let go, or they might [further] sort and split it up based on their assessment of comparative quality. My sense is that some lots are bought by individuals/companies who serve as distributors. Where this leads is that I'm not sure how much sense it makes to think in terms of Rooney knots vs. M&F knots. And it's constantly changing anyway, depending on supply. You actually may be making it harder than it really is.
I think the best place to start is by trying some different kinds of knots to figure out characteristics you like, such as 2-band vs. 3-band, knot diameter, loft, density, soft, scrubby, scritchy, floppy, springy, etc. If you're lucky, you'll resolve to a fairly narrow set of criteria that will makes selection fairly simple. If you're not lucky, you'll end up like me and revel in variety....
My experience with [Lee] is that he'll try to understand what you want and then refer to different batches/knots he has that have this or that "feel". My impression sometimes has been that knots "surface" and he remembers and/or can identify when/where they likely came from and what other brushes they might be most like. It's not science, but so far what I've received is exactly what I was given to expect.
Of course he can't give every batch a different name.
On the other hand, it has occurred to me that it would be nice if brushes could be identified to batches. That would make it a lot easier for the user community to discuss and compare experience with a more-or-less common frame-of-reference. [Here my tongue went into my cheek.] It could also be good marketing because collectors would likely go after multiple examples of the same style brush made from different batches, and all kinds of new brush lore could spin out based on real and imagined differences. Wouldn't that be fun?
Now that I think about it, they should identify knots to individual badgers.
