A writing impression is often left on the underlying paper beneath the page that was originally written on. This does depend on how hard the author pressed down on the original document. There are procedures that make the imprinted writing visible on the underlying paper that you can try on your own. Other methods such as electrostatic development, ultraviolet radiation, infrared radiation, filters and lasers are used by forensic laboratories with specialised pieces of equipment.
Lay the paper on a flat surface. Remove any lamp or light shining directly on the paper.
Hold a lamp or other lighting source next to the paper. Shine the light across the paper at a low angle, adjusting the angle and the distance until shadows form in the imprints.
Take a picture of the paper with a digital camera to capture the shadows. Print the picture to read the imprinted writing.
Remove the page from the tablet and lay it on a flat surface.
Sharpen a number two pencil.
Rub the pencil lead lightly across the page. The lead shades the raised areas on the paper and leaves the indentations from the original writing clear.