Grade 302 is a thick smooth paper, suitable for the removal of fine particles. This paper is made with 100% pure cellulose fibres that have been strengthened to resist the pressure when they are used in filter press systems. There is therefore no contamination danger during transfer steps. This high absorbency grade is twice as thick as Grade 301 with a bigger pore size. The extra thickness gives higher wet strength and loading capacity, enabling more precipitate to be held without clogging the filters and better handling. Grade 302 is also highly suitable for use in Buchner funnels and dye filtration.

This grade has a larger pore size than Grade 301, but with a lower filtration speed. Grade 303 also has higher absorption than Grade 301 is it used in general laboratory applications. Grade 303 is also found in agricultural and environmental laboratories for plant growth trials, soil testing and air analysis for monitoring specific contaminants and in the filtration of organic and sulfide precipitates.