preservation management of photographic collections 21 … · handling photographic media 4 cotton,...
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D A T E
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Preservation Management of Photographic Collections
21 September 2011
Preservation Management 2
Traditional photographs /Digital photographs
Identification
Storage enclosures
Storage environments
Must Have Resources 3
Handling Photographic Media 4
Cotton, latex or nitrile gloves must be worn when handling all photographic materials
Negatives should be handled in a well-ventilated room
Before removing a negative from an envelope transfer all catalogue to the new negative
Only pencil should be used to write on the new envelope
The emulsion side of the negative should be placed away from the envelope seam
Never re-use an envelope that has been used to store cellulose nitrate or cellulose acetates
6B pencil or permanent pigma pen
Gloves Do Matter 5
Cased Photographs 6
Daguerreotypes 7
Introduced in France 1839
Early 1840s – early 1860s
Whites/highlights are silver mercury
dark areas pure silver metal – highly polished
Silver mercury amalgam
Copper Plate
Silver Plated Surface
Daguerreotype 8
Malcolm Daniels, Curator of the Dept of Photographs at the Metropolitan Museum of Art (4.39)
C:\Documents and Settings\Rosaleen\My Documents\My Videos\RealPlayer Downloads\Daguerreotypes at the Met. - YouTube.flv
Ambrotype 9
1855 – 1865 – most popular in late 1850s
Wet collodion negative with dark background forms a positive image
Dark layer – applied or separate
Glass support
Collodion/silver salts
Varnish
Ambrotype Identification 10
No mirror-like surface
May have rose coloured glass
3D quality as the black/dark background is physically separated from the image highlights
Tintypes 11
1856 patented in US – into 20thc
Ferrotype or Melainotype
Inexpensive – street photographers
Japan BlackVarnish Sheet Iron
Japan BlackVarnish Collodion/ silver salts
Varnish Copal
Tintype Identification 12
Unmounted – magnet
Cased – magnet on glass
Can be coloured with dry pigments
Later tintypes inserted in paper cards – often card was embossed
Bends easily – fractures layer structure allowing rust to form
Cased Photo Storage 13
Mylar lift
Prints – paper base 14
Print Identification
30x magnification
Print Identification 16
One layer print
No Baryta layer – (barium sulfate)
One Layer
17 No binder No baryta layer
Paper fibers clearly visible
Matt surface
Print Identification – 1 Layer 18
Fibres visible no baryta layer
Platinum/Platinotype – 1 Layer 19
1873-76 US patents
Popular from 1890s –
Full grey scale range –– very stable
Matte surface
Platinum on/in paper surface
Platinum Identification 20
Range of greys – no fading
Catalyzes paper deterioration
Fibres clearly visible
Cyanotype 21
Blue
Print Identification 22
Two layer print – albumen print
Two Layer 23
Albumen (POP) 24
1850 Blanquart Evrard outlined process to French Academy of Sciences
1855 – 1895 ~ 85% of 19th century photos
Paper floated on egg white/ammonium or sodium chloride bath
To sensitize - paper then floated on a silver nitrate bath for 2 – 3 minutes
Rag paper – light weight
Albumen /photolytic silver
Albumen Identification 25
Paper fibres visible at 30X mag
Crack pattern
Albumen Identification 26
Most mounted on cards
Carte de visite - 2.5 x 4.25 “
Cabinet - 4.5 x 6.25”
Victoria - 3.25 x 5”
Promenade – 4 x 7”
Boudoir – 5.25 x 8.5”
Imperial – 6 7/8 x 9 7/8”
Panel – 8.25 x 4”
Print Identification 27
Three layer
Three Layer
28
Print Identification 29
Fibres not
clearly
visible
Baryta layer
30
Matte or Glossy Collodion POP 31
1890s – 1910s
Most frequently studio portraits – often oval
Baryta could be textured or pigmented
Sometimes called Aristotypes
Paper
Baryta
Collodion /photolytic silver
Silver Gelatin DOP 32
1880s –
Moved from silver chloride to silver bromide – baryta could be textured
Fibre and resin coated (RC) papers
Paper
Baryta (BaS04 + Gelatin)
Emulsion Silver Bromide
Gelatin Super coat
Mirroring 33
Photomechanical – NOT Photos 34
35
Postcard Photographs 36
37
Storage Enclosures: Paper 38
All materials should pass the Photographic Activity Test (PAT)
Buffered paper (pH 7 – 9.5) for all B/W photographic media.
Colour or processed diazo photographic materials may be stored in buffered envelopes that pass the PAT. The acceptable pH should not exceed 8.
Use side seam envelopes with emulsion side away from the seam
ISO 18902-2007
39
Molecular Sieves 40
Zeolites – aluminosilicates Porous compounds – trap molecules whose size is
compatible with their micropores
Acid Scavengers Acetic acid = Type 4A molecular sieve
Oxygen Scavengers
mixture of a metal powder (usually iron) and sodium chloride in bag Ageless Z
Exothermic
Storage Enclosures Paper – Advantages/Disadvantages
41
Opaque – protect from light but also means more handling as the photo has to be removed to be seen
Porous – off-gassing chemicals can escape – rh
Cost – generally less expensive than plastics Identification – write with pencil on paper
Microchamber paper – new – scavengers
charcoal, zeolites
ISO 18902
Storage Enclosures Plastic
42
All materials must pass the PAT
Safe plastics include polypropylene, polystyrene, HD polyethylene, polyester
Non-porous - can lead to ferrotyping
Avoid plastics with PVC, plasticizers and other additives
Beilstein Test – CCI Note 17/1
Trade names include Print File, Clear Vue
Magnetic albums 43
Kiss of Death!
ISO 18920 44
Photographic Negatives
Why Identify Negatives 46
Separate and rehouse negatives based on film base type
Identify stages of deterioration in order that priority rankings can be made for reformatting and/or cold storage
Metadata information for electronic copies
Health and Safety 47
Deteriorating cellulose nitrate and acetates have been known to cause health problems
Symptoms have included: Eye irritation, rashes, nausea, respiratory problems and others
Hollinshead, Patricia W., Ert, Mark D., Holland, Steven C., and Kathy Velo. 1987.
"Deteriorating Negatives: A Health Hazard in Collection Management," . Tucson, AZ: Arizona State Museum
http://www.statemuseum.arizona.edu/coll/healthhazard/phot_neg_hazard.pdf
Photographic Negatives 48
4 Major categories
Glass plate
Cellulose nitrate
Cellulose acetate(s)
Polyester
Glass Plate Negatives 49
Wet plate – collodion 1848-late 1870s
Hand coated just prior to use
Up to 18 x 22” = Mammoth Plates
Glass Plate Negatives 50
Dry plate – gelatin 1870s-1910s
Commercially produced
Dry Plate – Emulsion Lifting 51
Broken Glass Plates 52
Broken Glass Plate Housing From Carolyn Long Recommendations for Storage and Exhibition of
Photographic Materials Smithsonian 1989
Glass Plate Housing 54
Photographic Negatives 55
Cellulose nitrates (1889 – 1950s)
Cellulose acetate(s) (1925 – present)
Polyester (1960 – present)
Cellulose Nitrate Timeline 56
Film Type Last Year
Roll Film 1938
Portrait/Commercial Film 1939
Film Packs 1949
Pro 35mm Film 1951
*film may have been stockpiled so you will see nitrates after last year dates
*16mm was never manufactured in cellulose nitrate
Cellulose Nitrate Deterioration 57
Deterioration, once started, can only be stopped by putting negatives in cold storage.
Deterioration is accelerated by poor storage conditions;
High RH, high temperature, poor air circulation
Deterioration nitrate negatives can affect adjacent materials
Flammable
Cellulose Nitrate – Stage 1 58
Amber
discolouration
with fading of
filamentary
silver image
Cellulose Nitrate - Stage 2 59
Emulsion is
adhesive-like
Cellulose Nitrate – Stage 3 60
Gas bubbles, odour, and embrittlement
Cellulose Nitrate – Stage 4 61
Film softens,
viscous substance
is formed
Cellulose Nitrate – Stage 5 62
Brownish, acid powder
Cellulose Nitrate Storage Plan 63
Separate and store away from other photographic materials
Storage area should be exhausted to the outside
Do not store in plastic enclosures – use buffered acid-free paper envelopes that have passed the PAT
Deteriorating nitrates should be scanned
Cold storage
NFPA 40 64
2007 National Fire Protection Association
Standard for the Storage and Handling of Cellulose Nitrate Film
www.nfpa.org
Cellulose Acetate(s) 65
First used for 16mm amateur film
“Safety”
Ester family : Cellulose acetate propionate
Cellulose acetate butyrate
Cellulose triacetate
Cellulose Acetate Timeline 66
1923 Kodak cellulose diacetate 16mm film
1925 Kodak cellulose diacetate sheet film to 1940
1927 Kodak intro cellulose acetate propionate
1930s Other manufactures produce cellulose acetates
1936 Kodak intro cellulose acetate butyrate
1948 Kodak intro cellulose triacetate
Cellulose Acetate - Stage 1 67
Flat with no visible
deterioration
Cellulose Acetate - Stage 2 68
Slight or
moderate
edge curl
Cellulose Acetate - Stage 3 69
Characteristic vinegar smell becomes noticeable
Cellulose Acetate – Stage 4 70
Warpage
and
Shrinkage
3mm
Cellulose Acetate – Stage 5 71
Plasticizer migration
Cellulose Acetate – Stage 6 72
Emulsion separation
Anti-halation Layer 73
Cellulose Acetate Cross-Section 74
____________ Gelatin supercoat
______________ Top gelatin emulsion
______________ Lower gelatin emulsion
______________ Subbing layer – CN and CA
xxxxxxxxxxxx Cellulose acetate(s)
______________ Subbing layer
______________ Anti-halation /Anti-curl
Polyester 75
Polyethylene terepthalate
Introduced in the 1950s
Dupont introduced and called it Cronar – Kodak then bought Cronar and renamed it Estar
LE of 500 years (Acetates 100 years)
Negative Identification Methods 76
Non-destructive
Destructive
Is Edge Printing Visible? 77
Polarizer Test 78
Identifiable Notch Code? 79
Identified from Accession Records? 81
1889 Eastman Kodak – first cellulose nitrate roll film
1913 Nitrate sheet film produced
1923 First cellulose acetate film produced (16mm motion picture film only)
1939 Portrait and commercial sheet film – Kodak, last date of manufacture
1947 Cellulose triacetate first produced
1950 Nitrate motion picture film discontinued by Kodak
in U.S.
1955 First polyester film manufactured by DuPont
2000 Cellulose triacetate and polyester still in use
Characteristic Stages of Deterioration 82
Cellulose nitrate - 5 stages
Cellulose acetate – 6 stages
Destructive Testing 83
Diphenylamine Test (DPA)
Burn Test
Trichloroethylene Test
Diphenylamine Test 84
The DPA tests for presence of cellulose nitrate
Positive test is the formation of a dark blue/purple stain in the reagent
CCI Note 17/1
Advantages: very small sample size
Disadvantages: can get false positives
Cellulose Acetate Cross-Section 85
____________ Gelatin supercoat
______________ Top gelatin emulsion
______________ Lower gelatin emulsion
______________ Subbing layer – CN and CA
xxxxxxxxxxxx Cellulose acetate(s)
______________ Subbing layer
______________ Anti-halation /Anti-curl
Trichloroethylene 86
Allows for identification based on the differential densities of the plastic film bases
Least reliable as the densities of the plastics change with deterioration
Trichloroethylene is a carcinogen
CN sinks CA top Polyester middle
Cold Storage for Photographic Collections 87
Cellulose nitrate
Cellulose acetate
Color photographic media
Three Types of Cold Storage 88
1. Custom engineered walk-in cold vault RH control in vault
Difficult to maintain relative humidity
Expensive to operate
2. Walk –In Freezer with Gasketted Cabinets 89
RH control in gasketted cabinets
3. Microclimate Packing with Convention Freezer
90
RH control in storage package
Inexpensive
Based on Smithsonian Institute Research
Cold Storage Environment 91
Temperature:
below 0ºC (32 ºF)
generally around -18 ºC (0 ºF)
Relative Humidity:
30-50%
Why Should You Consider Cold Storage? 92
Increases life expectancy of collection
Rate of chemical deterioration decreases dramatically
Buys time to implement reformatting program
Allows for effective combination of reformatting (digitizing or traditional copy negs and long-term storage)
IPI Preservation Calculator 93
IPI Preservation Calculator 94
How to Proceed 95
1. Collection Survey
What type of negatives do you have?
What stage of deterioration?
This allows priorities to be drawn
What is the size of your collection?
96
Cellulose Acetate Autocatalytic Point
97
A-D Strips 98
99
Band 1-2 (blue green) – deteriorating but not a serious concern yet
Band 2 or higher (olive) – 0.5 autocatalytic point
Band 3 (yellow) – vinegar smell
Factors to Consider 100
1. Out of cold storage time
2. Access Copy negatives (polyester film base)
Digitizing
2. Walk –In Freezer With Gasketted Cabinets 101
Wilhelm Imaging – Iowa
City of Vancouver Archives
Cabinet 102
~50,000 5 x 7” cellulose acetate negatives
Pre-conditioned mat board
Retrieval 103
Igloo Cooler Temp – 3 remotes
3. Microclimate Packing with Convention Freezer
104
RH control in storage package
Inexpensive
Based on Smithsonian Institute Research
For small collections – or use an interim measure
Numbers 105
5x7” negatives
25 negs per package
6 packages per box
150 negs per box
18+ boxes per 20 cu ft freezer
2700+ negs per freezer
(Numbers courtesy of Betty Walsh, RBCM)
Packing System – Metaledge Inc 106
Colour slides
20 slides per page (PP)
25 – 30 pages per box
500 – 600 slides per box
20 box/freezer = 10 – 12K
www.metaledgeinc.com
Warm-up Times 107
Depends on thermal mass of package
e.g.. 2.5 cm thick = approx. 2 hours = one negative package not one box
Condensation on outer bag is normal
Always better to err on the long side of a warm-up time
US National Parks Service http://www.nps.gov/museum/coldstorage/html/intro1_1.html
108
Preservation Supply Companies 109
Carr McLean www.carrmclean.ca
University Products www.universityproducts.com
Hollinger Metal Edge www.hollingermetaledge.com