Ahlstrom-Munksjö’s qualitative grades of filter paper are recommended for use in analytical methods which determine or identify particulate constituents of a mixture irrespective of the amount present. Qualitative filter papers are often used in routine separation work that still requires high purity and consistent performance. These filter papers covers a wide range of laboratory applications, as liquids clarification, qualitative analytical separations for precipitates and buffers filtration, and are also used for soil analysis and in food and beverage testing. Wet-strengthened grades contain a reinforcement agent that increases their resistance to rupture when wet, such as in vacuum filtration, and their resistance when filtering acidic solutions. High Purity hardened filter papers grades 1288 to 1291 are also produced from cellulose with an alpha content of nearly 100% resulting in an ash content of <0,1%.

Grade 1288: Very fast filtering, open fiber matrix. For coarse and voluminous precipitates such as iron-aluminum- and chromium hydroxide; Si-determination in steel and pig iron analysis.

Grade 1289: Medium fast filtering, open to medium fiber matrix. Typical grade for qualitative tasks, coarser precipitates such as lead-, iron- and silver sulfide; alkali carbonates; calcium oxalate.
Grade 1292: Medium to slowly filtering, medium tight fiber matrix. For fast filtration of fine precipitates such as calcium oxalate, magnesium ammonium phosphate, coarser forms of barium sulfate.

Grade 1290: Slowly filtering, tight fiber matrix. For filtration of fine precipitates such as lead dioxide, calcium fluoride, nickel sulfide, zinc sulfide.

Grade 1291: Very slowly filtering, tight fiber matrix. For very fine precipitates such as barium sulfate, metastannic acid, cuprous oxide.