This is the second set I have bought because they are fantastic. I use the ‘inside’ brush the most and I suppose if there is a negative to them it would be to be careful using near a high heat source. I accidentally raised my hand with the brush in it when I was repairing some vinyl with a heat gun. Instantly melted my bristles.
What was interesting was because of that accident I had a closer look at how the bristles are made. Just the white top part melted with the darker underneath part left intact. The white tips are very fine, soft and give the brush tip volume and ability to safely clean a surface while foaming and spreading a cleaner into tiny groves. The black bottom part of the bristles is longer and stiffer giving support and reach to the soft section so the head doesn’t just collapse into a mop. As an artist with a long history using artist’s brushes I found this very intriguing and advanced. A ‘mop’ brush in the artist’s world holds large volumes of liquid to spread over large areas and would be good for detailing except they are held together with a metal ferrule of course. This ability to combine a mop like tip and a stiffer bristle underneath is what gives the interior brush such a great hard wearing and quick cleaning ability. I also love the ‘exterior’ brush and I also use it on parts of the interior too.