Glossary A–ZLetter T
Touch foil
A touch foil is a transparent film with an embedded sensor that is applied behind a pane of glass and makes it touch-sensitive.
It usually works capacitively and detects a finger through the glass. It is connected to a player or computer via a small controller.
A typical use is the interactive shop window: behind the pane is a screen or a projection, the foil sits on the inside of the glass, and passers-by operate the content from the street, even outside opening hours. Glass doors, display cases, counters or custom housings with large glass surfaces can likewise be turned into touch surfaces later on, without buying ready-made touchscreens.
How well the foil works depends on the thickness of the glass, the distance to the screen and the installation; with thick or double glazing, the technology reaches its limits. Rain, condensation or dirt on the outside of the pane can cause false triggers. Screen and foil must be precisely aligned so that each touch registers in the right place. Operators should test the foil on the actual pane before installation.