Make sure you do a through cleaning of those Kolinsky hair brushes and never use "India ink" or any shellacked ink on them, the pigments will travel down the upside down brush, in-between the hairs and into the ferule, where it'll accumulate, making it impossible to have a clean, thin tip, it's entire reason for being.
These are good brushes, so put a loop of wire, (do no dig into the paint and wood), string, or tape, and ALWAYS, hang them hair point down from a homemade or pre-made brush holder, after the Chinese and Japanese design.
I suggest you make the effort to buy a tube of Windsor Newton "art gel" to clean them very well with, or a tiny tube of "Masters" art soap.
Both will do the job, and each leaves a slightly oil like lubrication to condition the hairs with.
After rinsing, make a sharp, downward snapping action with your arm to throw out and down any excess moisture and then 'point' the hairs into a final sharp pin tip.
Again, store brush hairs downward and, Remember, if you do no have time to do your spotting And Clean Your Brushes, wait until you do have the time, to do it right.
Cheers.
