This sale is for diffraction grating film rolls. This sale is for a lot of 8"X24" sheets (I can also cut longer or shorter pieces on request. Every 5in" of sheet is separated by a faint line. The line does not distort or disturb the light quality of the diffraction. 8"X24" sheet of Double Axis Diffraction Grating that has 13,500 lines per inch sheet. Holographic Diffraction Gratings are highly efficient embossed Holographic Optical Elements (H.O.E.). Diffraction Gratings are used for direct viewing and analysis of spectra from different gas tubes and other light sources. The quality of the spectrum produced from our gratings is the brightest possible with minimal of distracting visual noise. These gratings are the principal component in a spectroscope and are used for experiments pertaining to the study of light and color. Project a spectrum using an overhead projector or 35mm slide projector for spectrum demonstration purposes. Use in conjunction with colored film gels for additive and subtractive color demonstrations.