TEST PROCEDURE FOR THE QUALITY OF PMS USING FILTER PAPER 1. Place 3 to 5 drops of the PMS on the filter paper 2. As the PMS dries observe for dirt or air bubbles The presence of dirt, air bubbles or both indicates poor quality PMS COST OF FILTER PAPER Filter papers can be purchased in any shop where laboratory wares are sold. They come in various sizes and shapes. The No. 1 size is recommended for the PMS test outlined above.