Grooved or Incised Media

Signal recorded by mechanically cutting or incising the surface of the carrier

Most common types:Cylinders and Platters

Also includes dictabelts and piano rolls

Cylinders

Earliest Format for Recording and Playback of Sound Edison tinfoil recording in 1877 Dominated recording industry into 20th

century

3 Common Types of Cylinders

Brown Wax or Soft Wax (ca. 1889-1902)

Molded or Black Wax (ca. 1902-1923)

Celluloid (ca. 1900-1929)

Brown Wax or Soft Wax (ca. 1889-1902)

Brown Wax or Soft Wax (ca. 1889-1902)

Made to be recordable and re-recordable, therefore are unique

Earliest commercially available were originals Later copies were commercially available, but in

limited quantities Usually have a waxy feel and smell Usually are 4 1/8” long and 2 1/8” in outside

diameter Usually held 2 minutes of recording Fragile, subject to breaking, warping and

distortion of grooves in high temperatures

Molded or Black Wax (ca. 1902-1923)

Molded or Black Wax (ca. 1902-1923)

Copies for playback only Hard compound was more durable

and produced louder playback Some waxy smell Usually 4” long Fragile, subject to breaking and

distortion

Celluloid (ca. 1900-1929)

Celluloid (ca. 1900-1929)

Copies for playback only Advertised as indestructible Made of nitrocellulose on a hard core

Not the same as nitrate film, ignition point is higher

But, if ignited in a fire, they are almost impossible to extinguish

Fragile, subject to shrinking and cracking in cold temperatures

All Cylinders Are Fragile

All Cylinders Are Fragile

They are susceptible to: Damage from previous playback or

rough handling Differential deterioration that results in

breakage Distortion from exposure to heat Mold from exposure to water or high

humidity Insect or rodent damage in poor

storage conditions

Handling

Wear nitrile gloves Lift from containers by

placing two fingers inside the cylinder, press gently to outside

Do not touch the grooved area

Minimize the amount of time fingers are in contact with the cylinder

Carry on a cardboard tube or dowel inserted through center and held with both hands

Proper Environment

Clean Cool Dry

Preferred Containers

Proper orientation: upright on one end Original containers are

almost always unsuitable (acidic)

Especially if lined with gauze

Rebox in container with a core that supports the cylindrical shape Keep original box with

the new one

Requires Immediate Attention

All valuable cylinders should be copied before storage Carriers are fragile Playback equipment is increasingly difficult to

locate Cylinders with differing materials in the

cores and recording surfaces are at most risk

Platters

Early form for recording sound Earliest version announced by Emile Berliner

in 1887 (10 years after cylinders) Eventually platters supplanted cylinders for

popular use

2 Primary Types

Instantaneous Discs(ca. late 1920s-early 1960s)

Commercially Issued Platters(ca. late 1900s-to date)

Instantaneous Discs(ca. late 1920s-early 1960s)

Aka, aluminum discs, lacquers, acetates, direct-cut discs, etc.

Recordable, therefore unique Laminated, metal or glass core covered

with a material soft enough to incise, but hard enough to withstand replay several times

Usually are 78s May play from inside to outer edge May have handwritten or partially

handwritten labels

Aluminum Discs(ca. late 1920s-early 1940s)

Aluminum Discs(ca. late 1920s-early 1940s)

Silver colored Usually 12” in diameter May have damage from previous

playback or rough handling May suffer from oxidation that can

damage grooves Fragile, but generally

chemically stable

Lacquer Discs, mistakenly called Acetates (1934-early 1960s)

Lacquer Discs, mistakenly called Acetates (1934-early 1960s)

Usually black nitrocellulose coating on aluminum, glass, or cardboard core

Usually 10”, 12”, 13”, and 16” in diameter May have damage from previous playback

or rough handling Glass cores are very vulnerable to

breakage Cardboard cores are vulnerable to water

damage Coating is vulnerable to plasticizer

exudation and delamination Very fragile, chemically unstable

All Instantaneous Discs are Fragile

Commercially Issued Platters(ca. late 1900s-to date)

Earliest recordings were single-sided Later recordings were two-sided (ca. 1907-to

date) Usually have a pre-printed label

Commercially Issued Platters(ca. late 1900s-to date)

Commercially Issued 78s(ca. late 1900s-late 1950s)

Commercially Issued 78s(ca. late 1900s-late 1950s)

Usually made of “shellac” “Shellac” described a number of

compounds: shellac, resins, gums, etc. Usually 10” or 12” in diameter Platters can become brittle with age Susceptible to mold from exposure to

water or high humidity Durable, if housed and stored

properly

Commercially Issued LPs (33 1/3 rpm) and 45s (ca. 1948-almost to date)

Commercially Issued LPs (33 1/3 rpm) and 45s (ca. 1948-almost to date)

LPs usually made of vinyl (polyvinyl chloride) Usually 10” or 12” diameter 45s usually made of vinyl or polystyrene Usually 7” in diameter Susceptible to scratching Susceptible to warping from exposure to heat Durable, if housed and stored properly

Handling

Wear nitrile gloves Grasp cover or container by bottom and

top to remove from shelf Support container from underneath

Flex sleeve gently to slide platter out of or into sleeve

Do not touch playing surface Support platter with fingers underneath

the center and thumb on edge Carry on a piece of cardboard that is

larger than the platter

Proper Environment

Clean Cool Dry Dark

Preferred Containers

Proper orientation: upright on the edge

Always remove shrink wrap

Original paper sleeves and covers are almost always unsuitable (acidic) Resleeve in

polyethylene or sturdy buffered alkaline paper

Preferred Containers

Box in sturdy phonograph boxes Do not overpack Keep original covers

and sleeves (if they have information) with the platter

Make sure accompanying materials are flat and free of staples, etc.

Shelving

If boxing is not possible, resleeve and place on shelves in album covers Opening of new sleeve should be

perpendicular to opening of album cover

Use full-size dividers 4”-6” apart for support

Do not shelve too tightly Do not allow platters to lean Do not lay platters flat

Requires Immediate Attention

All valuable instantaneous discs should be copied before storage Carriers are very fragile Playback equipment, especially appropriate

styli, is increasingly difficult to locate Lacquer discs are slightly more fragile than

aluminum discs

Please Contact Us

Weissman Preservation Center617-495-8596

http://preserve.harvard.edu

Jane Hedberg jane_hedberg@harvard.eduElizabeth Walters elizabeth_walters@harvard.eduLiz Coffey coffey@fas.harvard.edu