These smooth filter papers are made of refined pulp and linters with more than 95% alpha-cellulose content. The ash content of these filter papers is between 0,1 and 0,15%. They are used for routine analyses like clarification, determination of substances, but also as discs with a centre hole for technical applications. Grades with a wet burst resistance >30 kPa are referred to as wet-strengthened and are therefore suitable for pressure or vacuum filtration.

Medium fast rate of filtration, thin, smooth, increased wet strength. Used for acids; general vacuum or pressure filtration applications and less critical analyses; also used to assay the sucrose content in cane sugar solutions with a relatively low viscosity.