Soak materials Whatman paperDetection dog trainers often use Whatman filter paper as part of their training because of its highly absorbent and odor retaining properties. Here's why it's useful: Odor retention: Whatman filter paper is made to capture and retain substances, which makes it ideal for holding scents that dogs are trained to detect. Trainers can apply a scent to the filter paper, and because of its absorbency, the scent will remain potent for an extended period,