A Range of Paint Brushes...
... from Ammo of Mig Jiminez
Released under their own brand name, Ammo of Mig Jiminez have a series of synthetic paint brushes in different sizes, and with both round and flat heads.
Having tried these out, both for brush painting fine details and with the larger brush for applying some filters I found they worked very nicely and retain their shape very well. I know that real Sable brushes are considered the best quality but they are expensive. These are very reasonably priced (under 2 Euros each) and still give a good finish. Personally, I don't mind using a cheaper brush if it applies the paint nicely and if I make an error or am a bit 'rough' with it then you feel less guilty as having to replace it.
For the details of the different size/style brushes now available from Ammo, do check out their website.
My thank to Ammo of Mig Jiminez for my examples.