1. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation1 Digital Preservation Seminar A discussion of the article: Preservation Science Survey An Overview of Recent Developments in Research on the Conservation of Selected Analog Library and Archival Materials - by Henk J. Porck and René Teygeler Published in December 2000 by CLIR Note that the focus is on Analog materials. However, the findings apply in general to digital libraries as well, which exist on physical media having their own aging characteristics.

2. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation2 Tabular Summary of Survey IssuePaperFilm & Photo MaterialsMagnetic TapeGeneral (Other Materials) Decay  Pollution  Oxidation  Acidification  Ink Corrosion  Infestation  Pollution  Degradation  Chemical instability  Vinegar syndrome  Surface tarnish  Aging  Material decomposition  Life expectancy  Indoor air pollutants  Environmental factors -Humidity -Temperature -Light Treatment  Laser cleaning  Plasma treatment  Deacidification  Corrosion treatment  Natural insecticides  Laser cleaning  Cyanotypes  Disinfection  Disaster Recovery  Controlled atmosphere  Disinfection  Fumigation  High-temperature treatments  Pest control Storage  Microchamber  Polyester film encapsulation  Humidity Controlled Macrochambers  Climate-controlled environments  Light conditions  MicroChamber  Polystyrene products  Similar requirements and issues as photo & film  Climate conditions  Lighting  Materials testing  Polyethylene foam

3. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation3 Preservation Problem Makers Inherent –Natural decomposition characteristics of the material –Wear-and-tear from normal use Environmental –Temperature, Light and Relative Humidity –Air Pollution –Electro-Magnetic Radiation Organic –Pests –Molds –Fungi

4. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation4 Artifact Life Expectancy First rule of preservation: “Do no harm” Previous attempts at preservation and/or restoration have often resulted in further damage –Examples include Italian frescoes, Egyptian mummies, etc. Survey indicates that we are still far from finding acceptable (read: affordable & effective) tools Landfill Decomposition is a relatively new science that might provide more information about materials’ durability

5. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation5 Trends: Shift to large-scale, passive conservation Integration & cooperation in preservation management From hydrolysis to oxidation Backlog of film, photo, and tape preservation research

6. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation6 Gaps Large-scale damage prevention vs. individual artifact preservation Insufficient research on both better preservation techniques as well as on long-term effect of current techniques Does scanning documents for digital preservation accelerate the deterioration of the document itself (from electro-magnetic exposure)? Once we “digitize” an artifact for preservation, does the original suffer greater and faster degradation?

7. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation7 And More Gaps… The field of film, photo, and magnetic tape preservation does not have the well-established tradition in conservation treatment that paper does. –lack of experience/knowledge due to materials being newer –Most “solutions” are based on reformatting – Recent trend is to reformat analog materials into digital, which might result in artifact loss digital mass storage is widely used as the means to preserve radio/tv and similar media (tapes) –Difficulties in preserving the tapes themselves come from “secret” aspect of their composition –Businesses haven’t pursued preservation (no money in it?) except microfilm –Primary focus is on miniaturization, performance, capacity Caveat Emptor? –Canada wants manufacturers to notify archivists when digital media products will be discontinued and instruct how to migrate them without content loss. – Some professionals are pushing for a “shelf life” stamp on digital media so that assets could be managed intelligently But note that the overall path is still migration versus item preservation

8. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation8 Discussion: General Preservation Issues Big issue is volume –this can’t be successfully done on a page-by-page or item-by-item basis and still remain cost effective. $ $ Validity of life expectancy predictions Impact on triage process Particularly important for magnetic tapes EM field impact on digital media is known –sources are sometimes unexpected Infestation control requirements varies by climate and country –Insects –Fungi –Molds

9. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation9 Discussion: Triage Triage is required –large-scale vs. focused conservation efforts –Accidents happen… what about disaster recovery? –Budget constraints limit our options –International groups attempting to develop standards and guidelines SEPIA (Safeguarding European Photographic Images for Access) UPAA (Universal Procedure for Archive Assessment) But triage depends on being able to prioritize by urgency –Life expectancy of digital media is the Great Unknown –“Accelerated Aging” experiments have proven unreliable for other materials –Preserving the artifact does not necessarily mean preserving the information

10. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation10 Closing Comments Bottom line: –in many cases we are not sure how to genuinely preserve artifacts Implication for digital objects –prospects for their survival are slim at best, at least for current media Commercial and individual involvement –viability, profitability of preservation is needed before real success will be seen –Attempts by individuals to preserve usability of digital objects – including “antique” computers, video players, etc. – could be a key source of information for future archeologists

11. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation11 Paper Decay –Empirical data show storage environment is the key factor in decay –Problems range from chemical composition of paper and/or the ink (acid, e.g.), to deterioration due to pests, fungi, molds, etc., as well as to indoor air pollution –Results from experiments in aging paper do not necessarily apply to real-world experiences new techniques are improving value of research in this area Treatment –Coatings may damage more than they preserve –Gas treatments (for fungi) pose health hazards –Newer treatments (e.g., laser cleaning, insecticides) have unknown long-term effects Storage –Various options proposed, none of which are yet proven effective over the long term <--

12. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation12 Film & Photographic Materials Decay –Particularly susceptible to air pollutants –Heat & humidity accelerate deterioration –Some materials (acetate, nitrate) are very unstable Treatment –Blueprint fading can be reversed by dark-room storage, but is often harmed by other treatments –Effective fungicide treatments exist (formaldehyde and ammonium chloride) –Laser cleaning of daguerrotypes shows promise Storage –Tight enclosures can be as bad as open storage –Dry, cool, dark environments preserve film and photos best <--

13. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation13 Magnetic Tape Decay –Both media and content degrade over time –Subject to physical as well as EM harm –No empirical data available on real life expectancy of the media “Experience has often contradicted manufacturers’ claims.” [p 34] Treatment –Research hampered by industrial-secret aspect of the media –Disaster recovery experiments (e.g., from floods, fires) still in early stages Storage –Since media is acetate, nitrate, polyester or some combination, dry, cool, and dark environment is expected to be the best storage solution for preservation purposes (same needs as film/photo) <--

14. 29 Jan 2004/Joan SmithCS 791/891 Digital Preservation14 General (Other Materials) Decay –Indoor air pollution now recognized as an important factor in decay of artifacts –Temperature, relative humidity and light are the commonly known and studied problem-makers Treatment –Fungi – essential oils –Insects – fumigation bubbles or high temperatures –Bacteria – oxygen deprivation Storage –RH, temperature & light are critical but expensive, and difficult to maintain <--