They make brushes for artists, cosmetics, shaving, nail, dental - I think they are the largest brush manufacture in the world...
I've been using a lot of Da Vinci brushes lately as they are really excellent - one of my favourite brands, along with Raphael and Rosemary & Co, though of course there are many other excellent brush brands.
I took a photo to show a range of them together just to show size comparisons. I thought it might be helpful to show the studio brushes next to the travel brushes as I get a lot of questions about brushes.
Raphael 8040 sable size 4
Lamy Joy fountain pen
Da Vinci Junior flat size 6 (6mm)
Da Vinci Casaneo size 2
Da Vinci Casaneo size 0
Da Vinci red sable mop size 0
Da Vinci Harbin Kolinsky size 4
Da Vinci Maestro Tobolsky-Kolinsky sable size 5 and 8
Da Vinci Kolinsky sable travel brushes size 10, 8, 4 and 3. I use the 8 when sketching almost all the time.
Rosemary& Co R9 travel brush, squirrel quill.
I love to use natural hair brushes - sables and squirrels - but there are many great synthetic hair brushes available these days, including the synthetic squirrel Casaneo range, which come in many shapes and have also been released as a travel brush. The Harbin Kolinsky are part of the red sable range and are shorter than the Maestro range in either the studio or the travel brushes.
For more information on brushes, see my blog posts here or my website here
