Shellac

by

index

from https://lareviewofbooks.org, http://www.shellac-india.comand, and  http://www.obsoletemedia.org:

People like to crow about how analog records sound more “organic” than digital formats, but in the case of the 78, most of them are literally organic in origin. The traditional 78 manufacturing process relies on shellac, a resin secreted by the lac, a scaly insect from South Asia, loosely related to cicadas.

The Lac bug is a very small red parasitic bug that attaches itself to a small variety of trees.  The insect feeds on the sap of the tree and secretes the lac as a protective shell in which the female lay their eggs.

Once the lac is removed from the branches, it is crushed and washed with water to remove a once valuable red or bright orange dyestuff from it. It is then heated and forced through a sieve to extract the filtered resin. It is now gathered and rolled while it is still soft and pliable and stretched into long, thin sheets.

The stretched-out sheets are allowed to cool and are broken into flakes. This flake form allows fresh quality shellac to be prepared and avoid waste. The flakes are mixed with denatured alcohol to produce a liquid solution that can be applied with a paintbrush.

The earliest disc records were made of various materials including hard rubber. Around 1895, a shellac-based compound was introduced and became standard, typically composed of about one-third shellac and about two-thirds mineral filler, which meant finely pulverized rock, an admixture of cotton fibers to add tensile strength, carbon black for color, and a very small amount of a lubricant to facilitate mold release during manufacture. The production of shellac records continued until the end of the 78 rpm format, although other materials were used, including vinyl.

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