In the early part of the 20th century, calotype was the main process used to reproduce watercolors. Calotype, typified by a random and fine grain, is the oldest (1855) and one of the most delicate printing processes to use a photography-related procedure, the printing surface being a light-sensitized gelatin. The last firm to use this exacting but rewarding process closed in England in 1983. The main disadvatages of calotype were the limited number of impressions (only a few hundred) obtainable from each plate and the relative slowness of the process.