{"id":621,"date":"2017-05-18T14:34:37","date_gmt":"2017-05-18T19:34:37","guid":{"rendered":"https:\/\/dev.tsl.texas.gov\/conservation\/?p=621"},"modified":"2018-06-21T15:08:22","modified_gmt":"2018-06-21T20:08:22","slug":"deterioration-and-archival-storage","status":"publish","type":"post","link":"https:\/\/www.tsl.texas.gov\/conservation\/2017\/05\/18\/deterioration-and-archival-storage\/","title":{"rendered":"Deterioration and Archival Storage"},"content":{"rendered":"

May is Preservation Month, and here at TSLAC we\u2019re celebrating by launching several new environmental monitors throughout our building.\u00a0 Providing a stable environment is one of the best steps you can take toward safeguarding collections.\u00a0 By controlling temperature and relative humidity, you can slow the clock on natural aging processes and often avoid conservation treatment altogether.<\/p>\n

How does environment matter from a conservation perspective?\u00a0 Simply put, it impacts materials\u2019 mechanical and chemical stability.\u00a0 Mechanical damage may occur when fluctuations in temperature and relative humidity cause materials to expand or contract.\u00a0 Rapid cycling of temperature and moisture is especially problematic.\u00a0 This can lead to cracks, tears, and breaks.\u00a0 One household example of mechanical damage can occur when pouring very hot water into a cold glass causes the glass to break.\u00a0 This dramatic damage can also occur gradually over time if archival materials are improperly stored.<\/p>\n

\"Mechanical<\/a>

Mechanical damage is one factor at work in the pictured transcription discs. The discs\u2019 outer coating (cellulose acetate plastic) and inner core (glass) have reacted to their storage environment differently, causing severe cracks and losses. (Photo by Steve Kantner.)<\/p><\/div>\n

Chemical damage occurs when materials change or weaken at the molecular level.\u00a0 Chemical damage, in its many forms, generally speeds up in warmer, wetter conditions.\u00a0 Without sufficient heat or moisture, some deterioration processes may never start.\u00a0 Familiar examples of chemical damage driven by environmental conditions include yellow, brittle paper and silver mirroring in black and white photographs.\u00a0 In archives, a particular concern is iron gall corrosion, the process by which historical ink can eat through paper.<\/p>\n

\"Chemical<\/a>

Chemical degradation has caused the iron gall ink in this document to weaken its paper support. As a result, brown halos appear around heavily-inked areas, and losses are visible in the large letter \u201cG\u201d.<\/p><\/div>\n

Archival environmental standards for paper-based materials are 45 \u2013 55% RH, 65 \u2013 72 degrees Fahrenheit.\u00a0 While it\u2019s OK for these levels to drift gradually across seasons, short-term fluctuations should be minimized.\u00a0 Remember these environmental impacts as you safeguard your treasures.<\/p>\n","protected":false},"excerpt":{"rendered":"

May is Preservation Month, and here at TSLAC we\u2019re celebrating by launching several new environmental monitors throughout our building.\u00a0 Providing a stable environment is one of the best steps you can take toward safeguarding collections.\u00a0 By controlling temperature and relative … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[66,70,81],"class_list":["post-621","post","type-post","status-publish","format-standard","hentry","category-conservation-2","tag-preservation","tag-relative-humidity","tag-temperature"],"_links":{"self":[{"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/posts\/621","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/comments?post=621"}],"version-history":[{"count":1,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/posts\/621\/revisions"}],"predecessor-version":[{"id":624,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/posts\/621\/revisions\/624"}],"wp:attachment":[{"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/media?parent=621"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/categories?post=621"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tsl.texas.gov\/conservation\/wp-json\/wp\/v2\/tags?post=621"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}