The image is part of the Royal Photographic Society Collection. Even the most level-headed operator is tempted to take a larger number of pictures and to give less consideration to the arrangement of each picture. Sewell went on to note, in an age of wartime rationing, that 35mm is wasteful on account of the two bands of sprocket holes that border its usable image area. On a positive note, the 35mm format was identified as the spur towards vertical enlarger designs. The method starts with an over-exposed print that is fully developed, fixed and washed as usual.
Etching is achieved using a two-part aqueous solution.
Combined, this mixture will etch one print sized around 10x12in, provided that etching is done in four stages with rinses given between each dose. The process proceeds under strong white light so that its progress can be monitored. Termination is marked by the lightest highlights just clearing, though the full beauty of the print is not evident until after rinsing and fixing in plain hypo' acidified with potassium metabisulphite. Brometched prints are said to have superior longevity thanks to the fact that their images exist within the paper, not just on its surface. A novel ground-glass screen was announced in 1941 under the name of Dapei.