Thumbprint taking and fingerprinting – step by step
The art of fingerprinting or thumbprint taking is not rocket science, and anyone can perform this art.  The older way of doing fingerprinting or taking thumbprints was to use a form of ink and take a person’s fingers, one by one, and press them into the ink pad, and then make either a FLAT or ROLLED impression on a piece of paper.  Standardized fingerprint cards are what is/was acceptable to the FBI and DOJ (Department of Justice).  However, these days, live scan is the medium of choice for many. Fingerprint cards generally require rolled impressions, while journal entries require a flat thumb impression.
 
Livescan Fingerprinting
The beauty of live scan is that you can take each individual fingerprint as many times as you like, until you get a good, clear impression.  With fingerprint cards, if you goof just once, you have to start all over again with a new card.  Elderly people have unbelievably stiff arms and grab on for dear life when you try to roll their wrist around to take prints.  They apply such a force of resistance due to their terror about nothing, that you might have to take their fingerprints several times to get readable prints.  Live scan solves this problem.  The bigger question is that the organization you are submitting the fingerprints to is the one that gets to choose what medium they prefer for fingerprinting, and every organization has their own standards.
 
Journal Thumbprint Taking
In the old days, a type of ink that is hard to wash off was used for any type of thumbprinting ranging from booking criminals to taking journal thumbprints.  Now, an inkless substance can be used which leaves the appearance of ink on a piece of paper, but is easy to wash off a person’s hands. 

How to take a thumbprint
Taking a journal thumbprint is easy (unless someone has a stiff arm, and many people do), just take the right thumb, and hold it by it’s sides with your thumb and middle finger… then take your index finger and press down into your ink pad, and then press down onto the notary journal making a flat impression. It is easiest to have their thumb next to the edge of the table so the rest of their hand can go lower.  If the signer’s right thumb is not available, use their left thumb, and if the left thumb is not available, you can use a right finger. Just document whichever finger you used.  I had a client who’s hobby was experimenting with explosives in his apartment.  I had to use whichever finger was remaining in his case. There were not many choices by the way.

Fingerprinting step by step

I only know the old-school technique.  Take the person’s left hand, and roll each finger in the ink pad, one by one.  Then roll each finger on the fingerprint card.  Then, take the person’s right hand, and repeat the process.  Some cards require additional flat impressions of the thumbs.  For flat impressions, you can roll the thumb in the ink pad, but do not roll the thumb when printing — just hold the thumb above the card, and then press down quickly and firmly.  If you move too slowly, the person’s right or left hand might start to shake and blur your impression.
 
When you you need to be fingerprinted or have thumbprints taken?
If you are being notarized, then it is a good idea for security to have a thumbprint in the notary’s journal as evidence that the signer was really you (and not just pretending to be you).  Some states require journal thumbprints for particular documents.  Applications for professional licenses often require fingerprints.  To become a notary in California, you need to be fingerprinted.  Criminals generally need to be fingerprinted when they get booked or tagged for being a gang member.

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