Stouffer 21 Step Sensitivity Guide T2115 The Stouffer 21-Step Transparent Guide is the platemaker's choice. It serves as a gauge to evaluate the variables encountered in the exposure and processing of lithographic plates and photographic materials by contact. It indicates the direction and magnitude of exposure or processing adjustments necessary to achieve the desired results. It is also used with contact positives, silk screen, printed circuit boards, and most other photographic applications for judging results, determining speed and contrast of emulsions, and hardness of coatings. - Transmission Step Wedge , numbered , 1/2" x 5" - A quality control scale for determining standardizing the proper exposure and processing of photo sensitive materials. - Used with litho plates, photo polymer plates, silk screen stencils, printed circuit boards, film positives, photo print papers, and more. - Includes an exposure correction table mpn: T2115 Available for Express Shipping