The most the photographice papers: view this website, you will get more........

http://www.silverprint.co.uk/info/yespap.html

现在才明白Eugene Atget的照片的魅力，艺术家都是怀才不遇的家伙，40岁才从事摄影，可惜拍的照片没有人懂得欣赏，30年间所卖出去的照片是越卖越少有要，但他的精品就在晚年才成形。

Printing Out Paper (POP)
The first published formula for a printing-out silver chloride paper using gelatin binder was published bv Capt. Sir William de W. Abney in 1882, and was the logical successor to albumen paper, requiring daylight exposure to produce a burnt sienna-tinted image. The emulsion was mixed containing an excess of silver nitrate, which acted as a reservoir of silver, reinforcing the printed-out image. As with albumen paper, its process normally involved washing to remove excess silver nitrate, followed by gold toning, or gold and platinum, to produce a stable purplish image. Liesegang of Dusseldorf were the first company to take it to market in 1886, with the name 'Aristotypie'. Another POP paper researched by Joseph Barker of London was offered for sale in 1885 but failed to make any impact, before being taken up by Emil Obernetier in Germany.Eventually, in 1891 the Britannia Works, soon to be Ilford Limited, manufactured Barker's paper, and coined the marketing abbreviation POP which has stuck ever since. Eastman Kodak quickly came in with 'Solio' paper in 1892, and were still marketing its successor, 'Studio Proof Paper' in the 1980's. Self-toning versions of POP, containing gold salts, were available by the early years of the 20th century, and became the most popular in use.Papers using collodion as a binder ran alongside POP papers as replacements for albumen during the 1880s, and were produced mainly in the form of collodio-chloride paper, of low sensitivity and used for printing out. Toning with gold, or double toning with gold and platinum was also normally practiced, and surviving prints are very stable. Never as popular in use as gelatin paper, they were largely superceded by the 1890s, although lingering on as a minority product from some manufacturers - Leto, one of the Ilford subsidiaries, was still marketing 'Seltona', a self-toning collodio-chloride paper until the early years of the second world war.
(POP still hangs on in there in 2004 - Kentmere are now the sole producers in the world (maybe the universe?), and although production has been dogged by technical problems in recent years, stock should be available this year. Recent emulsion failures led their R&D department to attempt to track down the gremlin and a new variable has entered the complex state of POP emulsion technology - barometric pressure! Time and temperature, fair enough, chemical purity, OK, but the way the wind's blowing??)