Section 58(1)(b) in West Bengal Industrial Disputes Rules, 1958
(b)an impressed stamped paper of four annas [forty paise] (i.e, folio) [ or on demy paper/thick paper by affixing the adhesive stamp of equal value of folio] with an adhesive stamp of four annas [forty paise] affixed thereto for copies of documents containing 151 to 300 words, and