On November 18, Reli Heritage Preservation conducted an acidification research on the collected documents of Suzhou chronicle Archives.

In this research, 4 kinds of paper archives were sampled and tested. Each represented a special type: ancient book on handmade paper, rubbings on handmade paper, newspaper on machine-made paper, and including ancient books on handmade paper, rubbings, newspapers on machine-made paper and factory logs on machine-made paper. Testing results indicated:Suzhou Daily in 1992 was in worst acidification status, with pH value at 3.93, and paper seriously charred, brittle and mouldy.

Baopuzi in late Qing Dynasty published on traditional handmade paper bore a pH value of 4.14, also in a serious acidificated state.

The pH values of paper with similar preservation time of 80 years were relatively close. Just as Factory Log of Suzhou 4th optical instrument factory on machine-made paper and rubbings on handmade paper, with pH values of 6.09 and 6.23 respectively.

Rubbings and ancient books are widely circulated documents and historical preservation forms in China, and local Chronicles are also documents with historical preservation value. The investigation of acidification will provide scientific and reliable data reference for deacidification protection of literatures in the future.Reli Heritage Preservation will work hard with collection agencies, introducing advanced technology of the world, save precious documentations in China.