Eight new stamps were issued by the Department of Posts. ``The stamps have thematic relevance and international appeal. For collectors, the stamp on Indian musical instruments, with a backdrop of a panel of sculptures, will have special interest. It is worth investing your money in,'' explains Gupta.

In the International Year of the Ocean, another interesting release was Sea-Shells of Andaman and Nicobar Islands. The most beautiful and exotic of marine life, sea-shells are the protective external covering of molluscs -- a group of soft aquatic organisms. Molluscs are highly sensitive to pollution and many species face the threat of extinction. The stamp can be collected for the thematic series of sea, sea-shells and environment.

Naturalists will like thestamp on the `International Pharmaceutical Congress Association' with a picture of a neem tree. The release of the stamp coincided with the 50th congress of the Indian pharmaceutical industry held in Mumbai during December 10-13 as part of the golden jubilee celebrations of the Association. A stamp on the Connemara Public Library, Chennai, one of the five oldest libraries of India, was released on December 12.

Paintings, sculptures and ancient books manifest the highly advanced tradition of music in India. The set of four stamps on Indian musical instruments highlight this cultural heritage.

Musical instruments are classified into four main groups on the basis of how sound was produced: Tata Vadya (stretched stringed instruments like the veena, sarod, santoor, sitar, etc); aerophonotic hollow or wind instruments like the sankh and bansuri; Avananddha Vadya, where the sound comes from vibrations of stretched skin like drums, tabla, dholak, pakhawaj, etc., and Ghana Vadya, wherethe sound comes by striking solids against each other.

The stamp on Lieutenant Indra Lal Roy, the pilot who distinguished himself during World War I, can be collected for the themes of aviation or defence.

``It's not advisable to invest in first day covers, however attractive or meaningful they may be. There is a section for first-day covers for investors and exhibitors, and they can fetch money if they have passed through the postal system and have been actually operational,'' according to Gupta.