Just as with Badger or Horse Hair brushes, the knot shape, the design, the bristles themselves and how the brush is treated will determine whether it blooms or not. Generally thicker bristles or straight shape knots will bloom less than fan or bulb shape knots. All Boar knots soften with use as the ends split. So on to pictures. Old & New; the two on the left are fairly new knots while the two on the right are over a half century old. The far left is a replacement knot from TGN and most likely made by Zenith. These are all likely at least a half century old knots. Note that the fan shapes show more bloom than the straights. All new and still in break in phase. From Left:Omega, Zenith, Jayaruh with Omega Knot, Jayaruh with TGN (likely Zenith) knot.
Good looking stable of boar bristle @jar ! I searched for a straight non-bulb knot for my Rubberset400 replica. It's uncommon, no one sells them as a replacement knot. I don't want to say I settled, but I'm happy with the quality of Omega's so I used a new #10098.
999Shave from Etsy hand ties his own boar flat tops, but I do not believe he sells knots alone. I think @RyX tried. Maybe if more people bugged him.......
Are they flat tops or straights? Several places still do flat tops but they are more a fan version. Off to look. AbE: They appear to be flat tops. Shavemac also does flat tops and you can buy just the knot. Straights are just straight, about the same width at the tip as at the handle.
