Thursday, May 25, 2006

Lac beetles and your record player

Lac is a substance that is secreted by the insect "Coccus lacca" or "Laccifer lacca" often referred to as the lac beetle. It belongs to the family of mealy bugs called “Coccoidea”. For the record it is not actually a beetle its a butterfly larvae. This substance is collected by hand from a variety of trees that play host to the insect. The main lac host trees are Palas, Ber and Kusum. On an average three hundred thousand insects produce one kilogram of lac resin.
The bags of sticklac are heated over an open fire. As the lac melts, the bags of lac are squeezed with a tourniquet producing enough pressure to force the melted lac to the outside surface of the bag. Much of the lac is processed into thin sheets which are crushed into brittle flakes for preservation and storage. Here is a mp3 blog focusing on shellac 78s. And an eBook for kids.

The raw Lac called "Sticklac" is harvested from tree trunks and branches. The lac is then cleaned and processed into a variety of different forms including industrial shellac, food grade shellac (Ex. jelly beans) and even that stinky goo we use to finish old furniture. Yes, Shellac is non-toxic and is approved for use in food by the FDA. More here. and Here.

It was Edison that first used Shellac to make his recording cylinders, it was an innovation that followed had wax cylinders. Record gooves cut into shellac survived playback much better than wax as you might imagine. But this has been a decade of rapid media change...

During WWI, demand was high among the homesick troops for music from America. As a result special 12 and 16 inch radio transcription records playing at 33 1/3 were shipped to special army DJs and POWs in order to boost morale. They contained both important troop information and top hits of the day, often recorded free of charge by big artists such as Glenn Miller and the Andrews Sisters. These were called "V-discs." The "V" stands for Victory.

Shellac is brittle and V-discs often arrived cracked or broken, and as Japan invaded Asia the source of shellac, the Lac beetle of South Asia, became scarce. Shellac discs also had undesirable technical shortfalls: the playing time discs was limited to 10 minutes per side. With shellac there was a groove density limitation of about 80 per inch, more than that risked the groove walls collapsing. And making discs larger than 16 inches to increase playtime was just unfeasible. A new medium was needed! Enter a Polyvinyl Chloride also called PVC or more commonly... vinyl. (more on that tomorrow...)