I just love this 4 page brochure for Guenther Wagners of London advertising their Waterproof Drawing Inks. Indispensable for Black and White Artists, Architects, Engineers, Draughtsmen, Schools etc.
Just look at the Chinaman on the bamboo ladder adding the finishing touches to the 'Poster'
This leaflet is not dated, but would be from the 1920s. It is very large, over A4 size, and has unfortunately been folded and has a lot of tiny edge tears.