Knot size

My sweet spot is 22mm. Specially in my Semogue 830 and 1305.

I have everything from a 23mm to a 28mm knot. In addition, I have various loft sizes one as high as 60mm. With Shavemac you can order most any knot size and loft height. All of my brushes except for two are fan shaped. I find that I use some brushes specifically with certain soaps and creams.

I have 21mm boar, 2x24mm synthetic, and a 26mm boar. My absolute favorites are the boars, with my Razorock 26mm boar in olivewood being my favorite brush, followed VERY CLOSELY by the 21mm Zenith boar. I find I can get the same quality of lather from either brush, and that both provide a very luxurious appliacation.

Both are also fairly tall lofts(don;t have actual measurements), and both splay beautifully. Both are blonde boar, and both are made by Zenith. Both are extremely soft with lots of backbone, and both feel just wonderful to load, lather and apply.

For me, I think it is more about the quality of the knot, rather than the diameter. Clearly, my 2 favorite knots are worlds apart in terms of diameter, but are virtually identical in regards to hair type and quality.

I was actually surprised at how comfortable I found it to be applying lather to my head with such a small knot as the 21mm, but it performs beautifully and splays just enough that it doesn't seem to slow down the process even 1 iota...

My sweet spot is the 22-30mm range I'll enjoy the luxurious feel of my bigger brushes for a while, then desire the efficiency of my smaller ones. Variety keeps it interesting.

22 and 24 are my goldilocks sizes.

I like to stay in the 24-26mm range. Definitely no problem loading for a thick 3 pass shave, plus a huge handful extra for a cleanup pass.

This is an interesting topic. I think for me personally, I have several brushes I enjoy that happen to have different characteristics. I really like the Semogue 2000 (25mm), but the SoC boar not as much (24mm). I've recently acquired a Simpson Chubby 2 in best that I really like but have only used once. But there is one brush I prefer for face lathering specifically and it's the smallest knot I have - the Semogue 820 (22mm I think).

So I guess I just like having several nice brushes and I pick what I feel like that day.