BCTMP-tailored SCK paper for release liner

A method of manufacturing supercalendered kraft paper suitable for use as a substrate layer of an industrial release liner for adhesive labels, the method comprising

• mixing together
• bleached hardwood kraft pulp,
• bleached softwood kraft pulp, and
• bleached chemithermomechanical pulp,
• wherein the fiber furnish has an average length weighted fiber length in the range of 0.90 to 1.14 mm, when determined according to ISO 16065-2:2014,
• such that a pulp mixture is obtained, which has a fiber furnish determinable with standard ISO 9184-4 in conjunction with the standard ISO 9184-1,
• forming a paper web from the pulp mixture on a paper machine,
• reducing moisture content of the paper web in a press section,
• drying the paper web in a drying section, thereby forming paper, and
• calendering the paper,
• such that a supercalendered kraft paper is obtained having a basis weight in the range of 50 to 70 g/m2, and which contains the bleached chemithermomechanical pulp in an amount equal to or higher than 5 wt. % and the bleached softwood kraft pulp in an amount equal to or higher than 15 wt. %, when determined as dry matter content of the paper according to SCAN P 39:80,
• the supercalendered kraft paper thereby having
• a tear index in the cross direction of the paper higher than 5 mNm2/g, when determined according to ISO 1974,
• a transparency level equal to or higher than 40%, when determined according to ISO 2469 and
• a density in the range of 1040 to 1140 kg/m3, when determined according to ISO 534.