a brief introduction to photo preservation

Overview

I. The ImageII. The ObjectIII. In the ArchivesIV. Exercise

Why?

I. The Image

What’s in an image?I. The Image

Reading an Image

Five Ws

• Who• What • Where• When• Why

I. The Image

Reading an Image

Who?

• Photographer• Subject

I. The Image

Reading an Image

What?

• Present• Absent

I. The Image

Reading an Image

Where?

• Location

I. The Image

Reading an Image

When?

• Fashion• Technology• Absence

I. The Image

Reading an Image

Why?

• Context• Intention

I. The Image

Reading an Image

Why?

• Context• Intention

The "Carrying-in Boy," In an Indiana Glass Works, 1:00 A. M., Aug., 1908. Location: Indiana.National Child Labor Committee Collection

I. The Image

Reading an Image

Visual Elements

• Composition• Depth of field • Point of view • Rhythm • Color balance • Tonal range

I. The Image

II. The Object

Photo Basics

II. The Object

What is photography?II. The Object

What is a photograph?

• A complex physical object that has an image fixed via a photochemical process

II. The Object

Photograph Structure

Base: paper, glass, metal, plastic

Light-sensitive particles: silver, color dyes

Emulsion: gelatin, albumen, collodion

Baryta layer

II. The Object

Photo HistoryII. The Object

Photo HistoryII. The Object

Photo History

• Easier to create• Easier to duplicate• More accessible • Cheaper

II. The Object

Common Formats and Processes

II. The Object

Physical Evidence

• Polarity• Size • Base and mount• Color• Reflection• Microscopic appearance

II. The Object

Physical EvidenceII. The Object

Tintypes (ca. 1856-1930s)

• Collodion on blackened iron base

• Direct positive image

• Extremely popular during Civil War

II. The Object

Tintypes (ca. 1856-1930s)

• Cheap and ubiquitous • Often worn or

scratched

Identification:• Snip marks• Magnet test (on back)• Reversed image• Mainly portraiture

II. The Object

Albumen Prints (1850-1895)

• POP from wet collodion negatives

• Always mounted

• Tend toward sepia/yellowish

II. The Object

Albumen Prints (1850-1895)

• 80% of extant 19th-century prints– Cartes-de-visite– Cabinet cards

Identification:• Paper fibers• Cracking• Yellowing• Mount

Paper fibers visible30x magnification

II. The Object

Lantern Slides (1849-1950s)

• Glass slide

• Positive image

• Often used for educational purposes

II. The Object

Silver Gelatin DOPs (1885-present)

• Dominant 20th-century process

• Dozens of formats

Identification:• Neutral unless toned• Baryta layer (no paper

fibers visible)

II. The Object

Silver Gelatin DOPs (1885-present)II. The Object

Silver Gelatin DOPs (1885-present)II. The Object

Color Prints (1930s-today)

• Organic dyes• Many processes

Identification:• Characteristic

deterioration

• Unstable

II. The Object

Instant Photos (1948-today*)

• Photo printed from packet with negative, developer, base

Identification:• Adhesion markings or

developing pod• Coating flaws

• Unique• Unstable

II. The Object

Film Negatives

• Cellulose nitrate (1887-1950)

• Cellulose diacetate (1937-1956)

• Cellulose triacetate (1947-present)

• Polyester (1960-present)

Roll film

II. The Object

Film Negatives

Identification:• Notch codes• Other tests

• Cellulose bases unstable

Sheet film

II. The Object

Other ProcessesII. The Object

Digital Photos (1990-today)

• Sensor converts light to bits, computer renders image

• Digital preservation

II. The Object

Why?

• Preservation

• Access

• Context

II. The Object

Why?

• Photographs offer evidences and resonances not offered by other media

II. The Object

III. In the Archives

Handling

• Wear gloves• Provide support• Use only pencils• Gently remove from housing• Be aware of physical condition• Create and follow handling policy• Consider surrogates

III. In the Archives

• I: Enclosures (contact material)

• II: Furniture (proximity material)

• III: Environment

Levels of ProtectionIII. In the Archives

• Paper (envelopes, four-flaps) – Cheaper, blocks light, breathable– Viewing requires handling

• Plastic (polyester, polystyrene, etc. No PVC!)– Viewing without handling– Expensive, not for unstable items

• Must pass Photographic Activity Test (PAT)

EnclosuresIII. In the Archives

Enclosures

• Boxes and folders– PAT test– Proper support for format (long edge down or

flat)

• Ideally, separate photographs from other materials, and then by format (especially negatives!)

Balance condition/format, use, resources

III. In the Archives

Environment

• Temperature / relative humidity• Light (sunlight, UV light)• Pollutants (gaseous and particulate)• Biological (mold, fungus, pests)

III. In the Archives

Environment

• B/W silver gelatin: 65°F, 30-50% RH• B/W acetate negatives: 7°F, 30-50% RH• Chromogenic dye on paper: 36°F, 30-40% RH

Most good for the most items

III. In the Archives

Selected Resources

• General

Photographs: Archival Care and Management, Ritzenthaler & Vogt-O'Connor (2006)

Care and Identification of 19th-Century Photographic Prints, Reilly (1986)

III. In the Archives

Selected Resources

• General

SAA photo preservation workshop

Photo preservation and photo conservation listservs

III. In the Archives

Selected Resources

• Cartes de VisiteCartes de Visite in Nineteenth Century Photography,

Darrah (1981)

• FashionDressed for the Photographer: Ordinary Americans

and Fashion, 1840-1900, Severa (1995)

III. In the Archives

Selected Resources

• Gelatin silverA Guide to Fiber-Base Gelatin Silver Print Condition

and Deterioration, Weaver (2008)

• NegativesThe Acetate Negative Survey, Horvath (1987)

III. In the Archives

IV. Exercise

• Divide into three groups• Describe how to identify the photograph

using image and physical evidence (5 min)• Share your conclusions

Group 1

Group 1

Sixth-plate sized tintype, 1880s• Magnet test, snip marks• Image reversed – watch customarily on left• Jacket, tie, and hat match 1880s style

Group 2

Group 2

Carte-de-visite, early 1870s• Medium card stock, square corners (1869-1871)• Borders, common 1861-1869• Imprint with length-wise large type (common

1870-1875)• Shoes probably 1865-1875 • Photographers active in 1870s

Group 3

Group 3

Gelatin silver “real photo” postcard, ca. 1910s

• Neutral tonal range, silvering• Cyko postage stamp area (1904-1920s)• Divided back, no border: 1907-1915

III. In the Archives

Thank you!

http://slidesha.re/photopres

@archivistkevin