A clear plastic ruler with inches and cm on it. I used Inkscape to create the texture.
Sorry about that. Forgot to check that box, Thanks for letting me know! I will update it momentarily. To create the texture I used Inkscape and setup a grid of 0.125 inches with snapping enabled then started drawing lines. Switched the grid to mm and did the other side. Exported as PNG with transparency.
It looks like the image for the markings on the ruler is missing from the file, and since that controls how transparent the material is, the ruler just looks solid black.