Do you mean something like this http://www.bromba.com/indicard/indicare.htm http://www.bromba.com/indicard/indicare.htm? I remember that we used this in experim

Do you mean something like this http://www.bromba.com/indicard/indicare.htm http://www.bromba.com/indicard/indicare.htm? I remember that we used this in experiments with IR lasers to ensure that the beam was where we expected it to be.