How to distinguish whether you buy a good quality of brush filament?

HOW TO DISTINGUISH WHETHER YOU BUY A GOOD QUA;ITY OF BRUSH FILAMENT?
In the markets, there are so many quality of brush filament with such difference of price, So how do you know if you have bought the good quality of brush filament, even through the appearance is almost similar.
WE CAN FROM THE FOLLOWING ASPECTS TO DISTINGUISH:
1. APPEARANCE: GOOD QUALITY PRODUCTS WOULD BE MORE ROUND, GLOSSY.
2.FOLDING THE FILAMENT WHITS HANDLE FOR 10 TIMES.THE FOLLOWING ARE THE PICTURE COMPARE
Recycle Material Virgin Material
3. IT IS EASY TO BLEND THE FILAMENT 180 DEGREE,IT IS EASY RECOVERY BACK
4. FOR COLORFUL FILAMENT,IT NEVER FADES COLOR,SPECIALLY THE DARK BLACK COLOR
5. WHEN USING FILAMENT MAKING BRUSH,IT IS MORE ECO-FRIENDLY AND FLEXIBLE