- 1). Wipe the thumb clean with an alcohol wipe prior to taking an impression.
- 2). Ideally, the individual's forearm should be parallel to the floor when taking his impression. Ask him to look away to discourage him from attempting to guide his thumb himself.
- 3). Grasp the thumb securely and position it over the ink pad.
- 4). Press the thumb evenly into the pad, rolling it from one nail to the other. Ink should cover the tip of the thumb to the crease of the first joint.
- 5). Lift the thumb off the pad immediately after one roll. This will reduce smudging.
- 6). Press the thumb down onto the fingerprint card, rolling from one nail to the other.
- 7). Clean the remaining ink off the thumb using an alcohol wipe.