Wratten started his career as a school teacher and organist, and moved to London in 1861 to become a clerk at Joseph Solomon's Photographic & Optical Warehouse.
His work at the warehouse stimulated his interest in photography, and while there he learned how to use gelatin in a sensitized emulsion and began experimenting on his own.
During the course of his experiments, Wratten formed a partnership with Henry Wainwright (1877~) for the manufacturing and sale of photographic supplies.
Mees, a recent graduate of London University, was placed in charge of new product development, and soon introduced panchromatic plates sensitive to longer wavelengths.
To allow photography using particular wavelengths of light, Mees developed dyed gelatin filters which were placed between the plate or lens and the subject matter.