okay i found out the knot came out the bottom of my rex brush and technically the knot measured .875 inches or 22 mm. the glued hair on bottom measured 22 mm so do i need to get a 20 mm or a 22 mm? i am going to have to cork and weight the handle because its hollow.
Have to see some photos to see what you mean. Measure the diameter of the opening and subtract 1-2mm to get a knot size. That said, if a 22mm came out, a 22mm should go in. Do you have the ability to widen the hole? If so, you could go bigger. Good luck!