The term ‘gramophone discs’ is used to describe any disc format where an audio signal is recorded as a series of grooves which are read using a stylus and amplification system.

The basic arrangement of gramophone discs has not changed throughout their history. What has changed is the size of the discs, the speed at which they are played and the methods and materials used in their manufacture.

Various materials have been used in the manufacture of gramophone discs. These include (in chronological order): 

• Wax (compounded with other materials)
• Shellac (compounded with other materials)
• Cellulose nitrate
• Cellulose acetate 
• Polyvinyl chloride (PVC).

Another type of disc is the ‘instantaneous recording’ disc which consists of a metal substrate, usually aluminium, with a layer of cellulose acetate or cellulose nitrate overlaid on one or both sides.

Gramophone discs have recently been all but superseded by the new technology of the compact disc.

All materials degrade over time. We cannot control this inevitable deterioration, but we can control how fast it happens. Certain materials are susceptible to deterioration in particular ways just because of their properties, and other materials deteriorate as a result of particular environmental conditions.
For example:

• Shellac discs will shatter if they are dropped. 
• Cellulose nitrate and cellulose acetate are chemically unstable and give off nitric and acetic acid respectively as they degrade. Eventually the disc will deteriorate so that it cannot be played. 
• Instantaneous recording discs consist of a very thin layer of plastic over a metal substrate. As the plastic degrades, it shrinks, causing cracking of this layer. This makes the disc unplayable. 
• Polyvinyl chloride has a stabilising chemical included in it, but this eventually dissipates, leaving the plastic to degrade much like cellulose nitrate and cellulose acetate, but giving off hydrochloric acid instead.

As with any archival item, correct handling of gramophone discs will aid in preserving them for as long as they are required:

• Handle with care.
• Handle by the edges of the disc or the labelled area only.
• Use cotton gloves.
• Return the disc to the protective sleeve when you have finished using it.
• When playing gramophone discs, the correct equipment should be used in order to prolong their useable life. The disc should be clean and free from dust before playing, and the stylus should be set at the minimum weight possible.
• Labels should not be applied to gramophone discs. The protective sleeve should be labelled with identifying details such as item number and title.

Before placing a gramophone disc in protective packaging, it is important to ensure that the object is free of dust and that it is unaffected by mould, insects or active corrosion. Affected items should be isolated and advice on how to deal with them sought from your local National Archives of Australia office.
When packaging gramophone discs:

• They should always be stored in a protective sleeve which excludes dust and dirt.
• Archival quality materials should always be used when packaging archival records.
• If packaging a broken disc, make sure the edges of the disc do not touch as movement will cause chipping and loss of information.
• Make sure the box is not too big or too small, and the box is not too full or too empty, as both instances can cause damage.