Used with the Projectina ® Docustat DS-210, Cascade Developer are minute glass beads that are mixed with Indented Writing Toner. The mixture is then cascaded over Type IW film which has been placed over a surface suspected of containing indented writing. No physical contact is ever made with the document, so there is no chance that minute details may be damaged or destroyed. The toner/developer mixture adheres to the fine impressions in the document and extra toner/developer falls into the capture tray for clean-up and recovery.