For younger groups, using an index card to record fingerprints allows for mistakes or smudges as an index card is not designed with specific spots for each finger. The police use identification cards for official fingerprinting procedures at the police station. Officers may hand out a packet of cards to teachers if asked. The identification card has specific spots for the fingers of each hand set in a row at the bottom. Many identification cards have spaces for a palm print, also.
It is essential to have an initial copy of a fingerprint in order to identify a fingerprint left behind. A science project needs a control to base the found variables, the fingerprints themselves, against. Using an ink pad or thin paint, gently press the fingertips into the ink or apply a thin layer of paint to cover the tip. Carefully place the fingertip onto an index card or an identification card. Label the fingers as left thumb, index, middle, left ring and pinkie.
In a fingerprinting science project, there needs to be an item that has the fingerprints on it. For the younger students in preschool or kindergarten, tape a copy of a fingerprint to an item for easier identification. For older students, a glass, piece of painted wood or piece of absorbent paper easily produces fingerprints for careful discovery. Room-temperature glass is best as the heat in the fingers produces oils that leave fingerprints behind.
Once fingerprints are on the item to be tested, a powder is lightly sifted onto the item. The powder for the older students is either bi-chromatic powder, which is what professional crime scene investigators use, or magnetic powder. Chocolate drink mix powder is a good choice for teaching younger students, as they tend to put their fingers in their mouths more often than older students. Once the powder is sifted over the fingerprints, lightly blow the excess powder off. Gently press tape over the fingerprint and lift the fingerprint off the item and onto a clean white piece of paper. Compare the lines and swirls with the control fingerprints.