Ruma Pal, J.

1. THE petitioner Company carries on the business of manufacturing paper and paper board. According to the petitioner for the first time on 19-4-1983, the petitioner Company manufactured Chromo Board. THE manufacture of Chromo Board took place during the period 1-3-1983 to 28-3-1984. According to the petitioners the Chromo Board has a distinct characteristic which sets it apart from other types of paper board viz. that it has a surface suitable for fine screen half tone work and "is capable of accepting coloured printing specially in lithography thereby capable of accepting varnish coating".

2. ON 1/3/1983 a notification (hereinafter referred to as the said notification) was issued by the Central Government in exercise of powers under Rule 8(1) of the Central Excise Rules, 1944 by which rates of Excise Duty were specified in respect of various kinds of paper and paper board. There were 13 such types of paper and paper board, provided for in the Table to the said notification under separate headings. For the purpose of this application, the following two headings are relevant viz. 11 and 13 of the table to the said notification :- This read as follows :

The petiti