The business card and fingerprint scanner for your official use
Most print cards require the use of black ink. Print your name - Very Legibly - at the top, including full middle name, not middle initial. You sign in the "signature of person fingerprinted" box, and the technician signs and dates as "official taking fingerprint scanner". Complete the entries prior to fingerprinting. Be sure to include the business card of the fingerprint technician when you submit the card! If there is any question, the technician can then be contacted; as there is no place for the technician phone number on the card. Keep a card for yourself, a good fingerprint technician will offer a redo or refund if their work is rejected.
Fingerprint scanner is truly unique. The DNA of identical twins is identical; however, their fingerprint scanner differs! Our appearance changes dramatically over our lifetimes; our fingerprint scanner do not Sir Francis Galton, (British anthropologist and a cousin of Charles Darwin), in his landmark book "Fingerprinting, 1892" included one of the first classification systems for fingerprinting. He calculated that the odds of identical fingerprint scanner were one in 64 billion! Take good care of those fingertips, with the exception of that slight statistical deviation; they are truly unique.
Most fingerprinting is done with a specialized "inkpad" (not the inkpad used with rubber stamps!) and a device to hold the fingerprint card. In difficult cases, where the applicant has very shallow "ridges" - the Glass Slab and Roller replaces the inkpad. Slab and Roller allows the fingerprint technician to precisely control the amount of ink spread by the roller on the slab and subsequently "picked up" by the fingertips. Properly prepared, the smooth glass slab is almost transparent - even with the ink!
Prior to fingerprinting the hands should be washed (twice) with soap and hot water taking care to remove all soap, hand cream, etc. Next, a "pre-print" alcohol wipe is applied to the fingertips further drying the fingertips. A skilled technician will arrange the fingerprint card holder based on the height of the client, and position their client's stance such that the arm and wrist are able to turn smoothly. It is very important that the room be a bit cooler than comfortable - prints taken in a hot or humid environment will suffer from "running" and will not be acceptable. Avoid fingerprinting a seated subject.
Follow the directions of the technician. Most of all do not attempt to "assist" in the procedure. It is a mistake, and will degrade the prints if you add pressure, actively turn your finger or watch the process. It is really best if you close your eyes or look away. From my experience, watching will involuntarily cause you to "assist". An experienced technician will take a few "test" prints on scrap paper to judge the amount of pressure (different for applying ink / taking the fingerprint) and "twist speed" required for optimal results. Occasionally an individual print (one of 20 on a fingerprint card) will be substandard. "ReDo" tabs, rectangular peel and stick "overlays" are used to correct a misprint - no more than three per card is customary.