Ahlstrom manufactures high quality analytical filter papers for use in specialty end use applications. These custom designed qualitative grades are manufactured from top quality cotton linters using ultra-pure, reverse-osmosis water. Ahlstrom specialty analytical filter papers include pleated and non-pleated grades and are found in applications such as seed, asphalt and beer testing. All grades are manufactured in a strictly controlled environment that ensures high uniformity and high purity from filter to filter.