This certified MN 261 LIP filter paper is specially designed to meet the criteria of ASTM E 2187a and ISO 12863-2022. The paper meets both the conditioned (26.1 ± 0.5 g, standard deviation < 0.3 g) and dried (24.7 ± 0.5 g, standard deviation < 0.3 g) weight requirements. Filtration speed (20 ± 8 s), thickness (190 ± 20 µm) and roughness (2000 ± 500 ml/min) are also in accordance to the respective norms. It has been shown in a interlaboratory trial that the paper is suitable for the determination of the ignition propensity of cigarettes. LOT-specific certificates are available. The patented marking of each sheet makes it easy to determine the rough side, as required by the standards.