Plaster on a cut finger. Detectable plaster covering a cut on the finger of a woman who is chopping carrots. The plaster's blue colour allows it to be seen easily, especially if it falls off a wound during food preparation. The plaster also contains a metal strip (not seen here) which allows the large amounts of food to be checked by a metal detector for the presence of a plaster. Minor cuts to fingers are amongst the most common injuries.