This is a set of four (4) rare brushes designed specifically for Bromoil printing, a classic Pictorialist photographic process. They are used to ink the "matrix" produced by the process's unique chemistry. Made of hog's hair, with the customary angled stag's foot brush shape, they have lovely copper ferrules. These beautifully made, vintage brushes were produced by the L. Reusche company—I bought them in the early '80s, at the tail end of their production—and have not been available since that time.
Two of the brushes are size 20, with working surfaces about 1.5 inches in diameter. One is size 16, about one inch in diameter. The fourth is size 6, roughly 5/8 inch in diameter. All but the smallest have large copper ferrules that are partially oxidized, as usual. The ferrules could be cleaned, if you care!
I used the two larger brushes for a brief experiment with Bromoil, but they received very little use, so have maintained their shape perfectly despite being ink-stained. The two smaller brushes were never used. Generally, you start inking with the larger brushes and work your way down to the smaller ones to bring in details.
Bromoil brushes can be found from one or two obscure sources new, but they don't have the quality or copper ferrules of these brushes. Plus one new size 20 brush costs upwards of $110! These four brushes come in a Chinese-patterned box with a hinged lid. If it helps, I can try to locate my old tins of lithographic ink, in blacks and browns, which never dry out!