Size forecast charts for different textile surfaces, paper, plastic, etc. useful in a variety of conditions to accurately measure points, debris and imperfections on it. Other brand transparency charts can be viewed using a second generation copy from the main negative. Ours are the first generation Main charts for higher accuracy. Produced on a highly stable lithographic film. .007 rugged based polyester photo film The calibration of imaging equipment, a certified hglass scale and is used to calibrate the Edmund scientific 60 power microscope to measure each image.