Audiovisual Media Cheatsheet

Audiotape

Open Reel Audio

1/4" Open Reel (c. 1935 - 1980s)

Quarter inch open reel audio tapes of various reel sizes
1/4" open reel audiotape on varying reel diameters: 3", 5", and 7". Image courtesy of Aaron Coe, The Cutting Corporation.
Base Material
Acetate, paper, polyester, or PVC magnetic tape
Identification
Tape width: ¼"
Reel diameter: 2", 3", 5", 7", 10.5"
Preservation
  • Is susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Is prone to risks like mold, binder deterioration, physical damage, signal drop-outs, and, in the case of acetate-based tapes, base deterioration.
  • Tapes are also prone to blocking or pinning, which occurs when layers of tape adhere to adjacent layers.
  • Issues for many polyester-based tapes are print-through, sticky shed syndrome (binder hydrolysis), and soft binder syndrome.
  • Vinegar syndrome is a concern for many acetate-based tapes.

2" Open Reel (Late 1950s - 1980s)

Two-inch open reel audio tape with box
2" open reel audiotape. Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester or acetate magnetic tape
Identification
Tape width: 2"
Reel diameter: 3", 5", 7", 10.5", 14"
Preservation
  • Is susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Is prone to risks like mold, binder deterioration, physical damage, signal drop-outs, and, in the case of acetate-based tapes, base deterioration.
  • Tapes are also prone to blocking or pinning, which occurs when layers of tape adhere to adjacent layers.
  • Issues for many polyester-based tapes are print-through, sticky shed syndrome (binder hydrolysis), and soft binder syndrome.
  • Vinegar syndrome is a concern for many acetate-based tapes.

1" Open Reel (Early 1950s - 1980s)

Base Material
Polyester or acetate magnetic tape
Identification
Tape width: 1"
Reel diameter: 3", 5", 7", 10.5", 14", uncommon sizes
Preservation
  • Is susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Is prone to risks like mold, binder deterioration, physical damage, signal drop-outs, and, in the case of acetate-based tapes, base deterioration.
  • Tapes are also prone to blocking or pinning, which occurs when layers of tape adhere to adjacent layers.
  • Issues for many polyester-based tapes are print-through, sticky shed syndrome (binder hydrolysis), and soft binder syndrome.
  • Vinegar syndrome is a concern for many acetate-based tapes.

1/2" Open Reel (1950s - 1980s)

Base Material
Polyester or acetate magnetic tape
Identification
Tape width: ½"
Reel diameter: 3", 5", 7", 10.5"
Preservation
  • Is susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Is prone to risks like mold, binder deterioration, physical damage, signal drop-outs, and, in the case of acetate-based tapes, base deterioration.
  • Tapes are also prone to blocking or pinning, which occurs when layers of tape adhere to adjacent layers.
  • Issues for many polyester-based tapes are print-through, sticky shed syndrome (binder hydrolysis), and soft binder syndrome.
  • Vinegar syndrome is a concern for many acetate-based tapes.

Cassette / Cartridge-Based Audio

Continuous Loop Cartridges (Cart) (1959 - late 1990s; popular use, 1950s - 1970s)

Continuous loop cartridges
Carts. Image by Flickr user Roman, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0).
Base Material
Polyester magnetic tape
Identification
Tape width: ¼" (6.4mm)
Cassette: 133mm × 101mm × 23mm; smaller to larger sizes are less common
Preservation
  • Is especially susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Is susceptible to physical, biological, and chemical risks like stretching, breaking, drop-outs, mold, and binder deterioration.
  • Is subject to binding and tension problems due to binder lubrication and wind issues.

Compact Cassette (1963 - present; popular use, 1970s - 1990s)

Compact cassette
Compact cassette. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: approximately ⅛" (3.81mm)
Cassette: 4" × 2½" × ½"
Preservation
  • Magnetic tape is susceptible to physical, biological, and chemical risks like stretching, breaking, drop-outs, improper wind, mold, binder deterioration, and unintended recording.
  • Environmental conditions--especially heat, dust, and humidity--may also affect cassettes.
  • Is especially susceptible to damage from playback as it may jam in the playback deck and be "eaten," which can cause crimping and breaking during playback.

8-Track (1964 - early 1980s)

8-track cartridge multiple views
8-track cartridge: Pink Floyd "Atom Heart Mother" (U.K. issue). Image courtesy of Vernon Fitch, Pink Floyd Archives.
Base Material
Polyester magnetic tape
Identification
Tape width: ¼"
Cassette: 5¼" × 4" × ⅘"
Preservation
  • Is susceptible to physical, biological, and chemical risks like stretching, breaking, drop-outs, improper wind, mold, and binder deterioration.
  • Is also especially susceptible to tape binding due to lubrication loss and jamming in the playback machine.

Microcassette (1969 - present)

Microcassette against a compact cassette displaying difference in scale
Microcassette (foreground) and compact cassette. Note the difference in scale. Image by Flickr user Malcohol, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 3.0).
Base Material
Polyester magnetic tape
Identification
Tape width: approximately ⅛"
Cassette: 1 ⅞" × 1 ¼"
Preservation
  • Media and equipment obsolescence is a risk.
  • Environmental conditions--especially heat, dust, and humidity--may also affect cassettes.
  • Due to the relative fragility of the media, microcassettes have a projected lifespan of 2-10 years.

Digital Audio Tape (DAT) (1987 - mid 2000s)

dat cassettes
DAT cassettes. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: 4mm
Cassette: 73mm × 54mm × 10.5mm
Preservation
  • Biggest risk is format and playback equipment obsolescence.
  • Environmental conditions--especially heat, dust, and humidity--may also affect cassettes.
  • DAT has known playback problems that are typically related to mechanical alignment.

Digital Compact Cassette (DCC) (1992 - late 1990s)

DCC digital compact cassette player with DCC and case in foreground
DCC player with cassettes. Image by WikiMedia Commons user JPRoche, available under a Creative Commons ShareAlike license (CC BY-SA 3.0).
Base Material
Polyester magnetic tape
Identification
Tape width: ⅛"
Cassette: 4" × 2½" × ½"
Preservation
  • Biggest risk is format and playback equipment obsolescence.
  • Environmental conditions--especially heat, dust, and humidity--may also affect cassettes.

Cylinder

Wax Cylinder (late 1880s - c. 1915)

Group of brown wax cylinders
Wax cylinders. Image courtesy of Aaron Coe, The Cutting Corporation.
Base Material
Molded wax cylinder
Identification
Variable, but typically about 2¼" (diameter) × 4–4¼" (length)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • Brown wax cylinders are typically the softest among cylinder records.
  • Materials within the wax cylinder harden with age, causing the wax to become brittle.
  • Cylinders of different diameters cannot be played on the same machine; and, attempting to do so will damage the cylinder.

Plastic Cylinder (c. 1900 - c. 1929)

Plastic cylinders black and blue
Plastic cylinders. 4-minute plastic cylinders are found in a variety of shades. Those on the left are Indestructible brand; on the right are Edison Blue Amberols. Image courtesy of the Antique Phonograph Society.
Base Material
Molded cellulose nitrate cylinder
Identification
Variable, but typically about 2¼" (diameter) × 4–4¼" (length)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • Celluloid-based cylinders are prone to brittleness, and their cores (whether plaster or cardboard) are extremely fragile.
  • Cylinders of different diameters cannot be played on the same machine; and, attempting to do so will damage the cylinder.

Film

35mm (1893 - present)

35 millimeter film pack, slightly unspooled
35mm film pack (on inert polypropylene hub).
Image
B&W: Silver gelatin particles / Color: Yellow, magenta, cyan dyes
Base Material
B&W: Acetate, nitrate, polyester plastic film / Color: Acetate or polyester plastic film
Identification
35mm (1.38") wide
Preservation
  • If cellulose acetate is base, prone to acetate breakdown/vinegar syndrome.
  • Prone to damages like torn sprocket holes, damaged splices, scratches, and mag stock breakdown.

9.5mm (1922 - 1950s)

9.5 millimeter film perforations
9.5mm film strip. Three frames of cine film displaying the iconic central sprocket perforations. Image captured by Wikimedia Commons user Velela, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.5). Film content available in the public domain.
Image
B&W: Silver gelatin particles / Color: Yellow, magenta, cyan dyes
Base Material
Acetate or polyester plastic film
Identification
9.5mm (0.37") wide
Preservation
  • If cellulose acetate is base, prone to acetate breakdown/vinegar syndrome.
  • Prone to damages like torn sprocket holes, damaged splices, scratches, and mag stock breakdown.

16mm (1923 - present)

16 millimeter film in a metal can
16mm film (in a metal can). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Image
B&W: Silver gelatin particles / Color: Yellow, magenta, cyan dyes
Base Material
Acetate or polyester plastic film
Identification
16mm (0.63") wide
Preservation
  • If cellulose acetate is base, prone to acetate breakdown/vinegar syndrome.
  • Prone to damages like torn sprocket holes, damaged splices, scratches, and mag stock breakdown.

8mm (1932 - present)

8mm film unspooling detail image of sprockets
8mm color film. Note the oblong film sprocket perforations. Image by Flickr user Ian, available under a Creative Commons Attribution-NonCommercial license (CC BY-NC 2.0).
Image
B&W: Silver gelatin particles / Color: Yellow, magenta, cyan dyes
Base Material
Acetate plastic film
Identification
8mm (0.31") wide
Preservation
  • Since cellulose acetate is the base, it is prone to acetate breakdown/vinegar syndrome.
  • Prone to damages like torn sprocket holes, damaged splices, scratches, and mag stock breakdown.

Super 8mm (1965 - present)

Super 8 film detail
Super 8 film (detail). Note the square sprocket perforations. Image by Flickr user Edgar Vonk, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA).
Image
B&W: Silver gelatin particles / Color: Yellow, magenta, cyan dyes
Base Material
Acetate or polyester plastic film
Identification
8mm (0.31") wide. Larger image area and smaller sprocket holes than regular 8mm film
Preservation
  • If cellulose acetate is base, prone to acetate breakdown/vinegar syndrome.
  • Prone to damages like torn sprocket holes, damaged splices, scratches, and mag stock breakdown.

Optical Media

LaserDisc (LD) (1978 - late 1990s)

Laserdisc in sleeve
Laserdisc. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Acrylic disc
Identification
Approximately 12" (30.4cm) in diameter
Preservation
  • LaserDiscs are subject to mechanical and surface contaminants.
  • Discs may exhibit surface-crazing, a milky white, lattice, or spider web-like pattern.
  • Can suffer from laser rot, where the aluminum loses its reflectivity and the quality of the playback signal degrades.
  • Should be regularly checked for data degradation.

Compact Disc (CD) (1982 - present)

Three compact discs
Compact discs. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polycarbonate plastic disc
CDR/CDRW may use dyes in surface layer
Identification
120mm (4.7") diameter; 1.2mm thick
Preservation
  • Surface scratches, gouges, and smudges can inhibit playback of the disc.
  • Disc rot can occur when aluminum layer oxidizes, leading to the loss of data.
  • Should be regularly checked for data degradation.
  • Should be stored in cool, dry, and dark conditions.

MiniDisc (MD) (1992 - c. 2013)

Minidisc front and back views
MiniDisc cartridge (front and back view).
Base Material
Magneto-optical disc
Identification
Disc diameter: 64mm
Cartridge: 6.8cm × 7cm × 0.5cm
Preservation
  • MiniDiscs' compression scheme is both proprietary and unpublished, putting the content at some future risk of obsolescence.
  • Any copies—even digital copies—will be more compressed than the master disc and have lower audio quality.
  • Should be regularly checked for data degradation.

DVD (1995 - present)

Two DVD-Rs
DVDs. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polycarbonate plastic disc
DVDR and DVDRW may use dyes in surface layer
Identification
120mm (4.7") diameter; 1.2mm thick
Preservation
  • Surface scratches, gouges, and smudges can inhibit playback of the disc.
  • Should be stored in cool, dry, and dark conditions.
  • Should be regularly checked for data degradation.

Phonograph Record

Shellac Disc (1897 - late 1950s)

Shellac disc with original fiber board slip
Shellac disc (with original fiberboard sleeve). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0).
Base Material
Shellac-based disc
Identification
7"; 10"; 12"; 16" (diameter)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • Tend to become brittle with age and are susceptible to damage by mold and acidic substances.
  • When cleaning, DO NOT use fluids that contain alcohol as it can dissolve the shellac.
  • Original sleeves are not recommended for long-term storage and should be assumed to be acidic.

Aluminum Disc (Late 1920s - 1940s)

Aluminum disc photographed with ruler for scale
Aluminum disc. Courtesy of Jack Brighton, Illinois Public Media / WILL.
Base Material
Uncoated aluminum disc
Identification
10"; 12"; 16" (diameter)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • During playback, special care must be taken to preserve the signal etched into the relatively soft aluminum.
  • High humidity and temperatures can adversely affect these discs by creating prime conditions for corrosion and fungal growth.
  • Discs can be damaged by attendant materials like acidic cardboard (exterior) sleeves and non-archival plastic or paper (interior) sleeves.

Lacquer Disc (Late 1920s - 1970s)

Voice O Graph home recording lacquer disc
Voice-O-Graph home recording lacquer disc. Image courtesy of Aaron Coe, The Cutting Corporation.
Base Material
Aluminum, steel, glass, or fiberboard disc laminated with lacquer (cellulose nitrate or acetate cellulose)
Identification
7"; 8"; 10"; 12"; 13"; 16" (diameter)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • The nitrocellulose laminate can swell and possibly delaminate when exposed to high humidity or water.
  • May suffer from plasticizer loss, which causes the disc coating to become brittle and can lead to delamination.
  • All lacquer discs are fragile, but glass cores are especially so and can easily break if not handled gently.

Vinyl Disc (Late 1940s - present)

Microgroove vinyl record
Vinyl record.
Base Material
Polyvinyl chloride (vinyl) or polystyrene disc
Identification
7"; 10"; 12" (diameter)
Preservation
  • Is susceptible to warpage, breakage, groove wear, and surface contamination.
  • Is especially prone to scratches and abrasion due to its relatively soft material.
  • Can be damaged by attendant materials like acidic cardboard (exterior) sleeves and non-archival plastic or paper (interior) sleeves.

Videotape

Open Reel Video

2" Open Reel (1956 - early 1980s)

Two-inch open reel video reel with plastic case
2" open reel videotape (with plastic case). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: 2"
Reel: ~12" (diameter)
Container: 15" x 15" × 4"
Preservation
  • Spongy container liner can decay into a gummy substance that is difficult to clean off of the tape.
  • Is especially susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Prone to risks common to other types of magnetic media, such as mold, binder deterioration, physical damage, and signal drop-outs.
  • Is especially vulnerable because the format is long obsolete and playback equipment is hard to find.

1" Open Reel (1963 - mid 1990s)

One-inch open reel video plastic case
1" open reel videotape (with plastic case). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: 1"
Preservation
  • May be misidentified as 1" audiotape.
  • Is especially susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Prone to risks common to other types of magnetic media, such as mold, binder deterioration, physical damage, and signal drop-outs.

1/2" Open Reel (1965 - early 1990s)

Half inch open reel video
1/2" open reel videotape. Image by Flickr user windthoek, available under a Creative Commons Attribution NonCommercial ShareAlike license (CC BY-NC-SA 2.0).
Base Material
Polyester magnetic tape
Identification
Tape width: ½"
Reel, small: 5" (diameter) / reel, large: 7¼" (diameter)
Container, small: 5½" square × 1" / container, large: 8⅜" square × 1¼"
Preservation
  • Is especially susceptible to risks associated with age, hardware, and equipment obsolescence.
  • Prone to risks common to other types of magnetic media, such as mold, binder deterioration, physical damage, and signal drop-outs.
  • Half-inch open reel tapes are known to have problems with sticky shed syndrome.

Cassette / Cartridge-Based Video

U-matic / U-matic SP (1971 - c. 2000) / (1986 - c. 2000)

U-matic cassette and case
U-matic cassette (with case). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: ¾"
Cassette, small: 7¼" × 4⅝" × 1⅕" / cassette, large: 8⅝" × 5⅜" × 1⅕"
Preservation
  • Is susceptible to damage from mold, binder deterioration, and other physical and biological issues.
  • Older tapes are susceptible to signal loss.

Betamax (1975 - late 1980s)

Betamax cassette with slip case
Betamax cassette (with slip case). Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: ½"
Cassette: 6⅛" × 3¾" × 1"
Preservation
  • Older tapes are susceptible to signal loss due to their age.
  • Is susceptible to damage from mold, binder deterioration, and other physical and biological issues.

VHS / S-VHS (1976 - present) / (1987 - late 1990s)

VHS cassette with manufacturer's original cardboard slip case
VHS cassette (with original cardboard slip case). Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: ½" (12.7mm)
Cassette: 187mm × 103mm × 25mm
Preservation
  • Older VHS tapes are susceptible to signal loss due to age.
  • Is susceptible to damage from mold, binder deterioration, and other physical and biological issues.

Betacam / Betacam SP (1982 - present) / (1986 - present)

Betacam SP cassette - small size
Betacam SP cassette. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: ½"
Cassette, small: 6¾" × 4⅜" × 1⅕" / cassette, large: 10⅝" × 6⅜" × 1¼"
Preservation
  • Older tapes are susceptible to signal loss due to age.
  • Is susceptible to damage from mold, binder deterioration, and other physical and biological issues.

Video8 / Hi8 (1984 - late 2000s) / (1989 - 2007)

Video8 cassette
Video8 cassette. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: 8mm
Cassette: 3⅔" × 2⅜" × ½"
Preservation
  • Tape is prone to stretching.
  • Hi8 ME tapes are especially prone to durability problems.
  • Is susceptible to damage from mold, binder deterioration, and other physical and biological issues.

D-2 (1988 - 2000s)

D2 cassette pictured with DAT for scale
D-2 cassette (left) with DAT (foreground, right) for scale. Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: ¾"
Cassette, small: 6¾" × 4¼" × 1⅓" / cassette, medium: 10" × 5⅞" × 1⅓"
Preservation
  • Is subject to the same concerns as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.
  • Is subject to the threat of obsolescence.

D-3 (1991 - present)

D3 cassette with case
D-3 with case. Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: ½"
Cassette: 8¼" × 4⅞" × 1"
Preservation
  • Is subject to the same concerns as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.
  • Is subject to the threat of obsolescence.

Digital Betacam (1993 - present)

Digital Betacam cassette
Digital Betacam cassette. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: ½"
Cassette, small: 6⅛" × 3¾" × 1" / cassette, large: 9⅓" × 5⅔" × 1"
Preservation
  • Is subject to the same physical issues as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.

MiniDV (1995 - late 2000s)

MiniDV cassettes
MiniDV cassettes. Image by Lori Dedeyan, available under a Creative Commons Attribution-NonCommercial-ShareAlike license (CC BY-NC-SA 2.0). Courtesy of UCLA Library Special Collections.
Base Material
Polyester magnetic tape
Identification
Tape width: ¼"
Cassette: 2½" × 1⅞" × ⅖"
Preservation
  • Is subject to the same physical issues as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.
  • The format's thin tape makes size and durability also a concern.

DVCPRO (1995 - present)

DVC Pro cassettes
DVCPro cassettes. Image by Flickr user DRs Kulturarvsprojekt, available under a Creative Commons Attribution ShareAlike license (CC BY-SA 2.0). Courtesy of the Danish Broadcasting Corporation.
Base Material
Polyester magnetic tape
Identification
Tape width: ¼"
Cassette, medium: 3⅘" × 2 ½" × ½" / cassette, large: 4⅞" × 3" × ½"
Preservation
  • Is subject to the same physical issues as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.
  • Is subject to the threat of obsolescence.

DVCAM (1996 - present)

Digital video cassette varieties
Digital video (DV) cassettes, left to right: DVCAM (large), DVCPRO (medium), MiniDV. Image by Wikimedia Commons user Grm wnr, available under a Creative Commons Attribution-ShareAlike license (CC BY-SA 3.0).
Base Material
Polyester magnetic tape
Identification
Tape width: ¼"
Cassette, small: 2½" × 1⅞" × ½" / cassette, large: 4⅞" × 3" × ½"
Preservation
  • Is subject to the same physical issues as analog tapes—stretching, breaking, drop-outs, mold, binder deterioration, and unintended recording.
  • Is subject to the threat of obsolescence.

Wire Audio

Wire (1898 - early 1960s)

Wire on different sized spools
Wire recording. Image courtesy of Aaron Coe, The Cutting Corporation.
Base Material
Magnetized steel or stainless steel wire
Identification
Wire: up to 7200ft
Reel: 2 3/4" to 3 3/4" (diameter); 3/4" to 1 1/4" (thickness)
Preservation
  • Has most common issues with wire becoming tangled and/or broken.
  • Rust can impede signal retrieval or weaken the already thin wire and cause the wire to break during handling or playback.
  • Is subject to print-through damage, which occurs when the magnetized signal from one section of the wire migrates to lower sections and leaves a sonic imprint.