A filter paper is a cellulose sheet that has many pores and is used in laboratories for filtering solids from liquids or gases. The paper functions through trapping of solid particles while the liquid moves through its pores resulting in clear filtrate. It is applied in chemical, pharmaceutical, microbiological, food, and environmental laboratories, where it facilitates analysis (quantitative and qualitative) and gravimetric testing. There are many types of filter papers with different pore sizes for various uses in research laboratories.