Julie Nowlan, age 11, of Visalia, California, for her question:

What exactly is shellac?

This is a story about creatures that look like miniature scales and shells. They are called scale insects    and some species produce the glossy varnish known as shellac. The various scale insects live on favorite trees, feeding on liquid sap. Some species are rated as pests because their feeding habits weaken orchards and ornamental trees.

The useful scale insects that produce shellac live in India and Burma, the Philippines and northern Formosa. There they are encouraged to live freely in the wild, where they thrive on fig and banyan trees, soapberry, acacia and sometimes other forest trees. The blind, helpless little sap suckers are unable to move around. They overcome this problem by covering themselves with shells made of lac. This is the natural resinous material we use to make shellac.

When the eggs of the lac insect hatch, the larvae establish themselves on twigs of their favorite trees. They secrete a tacky substance around their soft bodies, which hardens in the air. Then they spend the rest of their lives anchored to the spot, inside their scaley shells. There is no need to roam because they have tough beaks to extract sap from the trees. These lac insects tend to crowd together and sometimes twigs are covered with half inch layers of their shells.

The encrusted twigs are harvested before the larvae mature. Naturally some are left to produce offspring for the next generation. The twigs are broken off and removed from the tree    and the next job is to remove the valuable lac from the woody debris. The harvest may be stuffed into canvas sacks and heated over hot charcoal. The partially melted lac is squeezed through the canvas. This may be repeated several times to extract all the thick, orange colored lac.

At this stage it is called seed lac. Usually it is warmed and workers stretch it into thin sheets that harden as they cool. The sheets are bashed into flakes and packaged for processing. Spreadable shellac is made by mixing lac flakes with alcohol. Its natural color is orange but it can be bleached to make white shellac, which is colorless.

It takes the scaley shells from about 150,000 lac insects to produce one pound of shellac. And the world uses 90 million pounds of the tough, shiny stuff every year. This requires the scales from about 13 million million little lac insects.

We use shellac for other things besides adding shiny surfaces to indoor furniture. It may be added to glossy varnishes, sealing wax and certain printing inks. Some is used in electrical insulating materials. Before man made plastics became so popular, shellac was used to mold buttons, plastic flowers and to make phonograph records.