Requirement 5
Requirement
Fingerprinting
Three Basic Types of Fingerprints
Show your counselor that you can identify the three basic types of fingerprint patterns and their subcategories. Using your own hand, identify the types of patterns you see.
Fingerprint Pattern Types
Fingerprints are classified into three basic types—loops, arches, and whorls—based on the patterns made by the ridges that cover the skin of the fingertips. Learning to recognize these general patterns and their subcategories is not hard. Review the examples in the images below, then complete the worksheet linked below to demonstrate to your counselor that you can identify the three basic fingerprint pattern types. Be sure to identify the pattern types of your own fingerprints as well.
Loops
Loops are fingerprint patterns in which ridges enter from one side, curve back, and exit on the same side. They can lean toward either the thumb or the little finger. There are two types:
- Radial loops slope toward the thumb (same side as the radius bone).
- Ulnar loops slope toward the little finger (same side as the ulna bone).
Identifying which hand the print comes from is necessary to tell the two apart.
Loops are the most common fingerprint pattern, making up about 65 percent of all fingerprints.
Arches
Arches have ridges that enter from one side of the finger and exit on the other.
- A plain arch has a slight rise or wave in the center.
- A tented arch has a sharper, more upright angle or spike in the middle.
Plain arches are simple to identify, but tented arches can look similar to loops. Remember: To be a loop, a ridge must curve sharply back toward the side it entered. If the ridge flows straight across the print—even with a noticeable rise—it’s an arch.
Arches are the least common fingerprint pattern, making up only 5 percent of all fingerprints.
Whorls
Whorls have ridges that form circles, spirals, or ovals, and they make up about 30 percent of all fingerprints.
- A plain whorl has one or more ridges that form a complete circuit and includes two deltas. An imaginary line drawn between the deltas will touch a ridge in the circuit.
- A central pocket loop whorl also has two deltas, but the imaginary line between them does not touch the recurving ridge because of a noticeable obstruction or angle in the pattern.
- A double loop whorl contains two separate loop formations, marked by two deltas and two distinct sets of “shoulders.”
- An accidental whorl includes two or more different pattern types or does not fit the definition of any other category.
Fingerprinting Pattern Worksheet
Now that you have learned how to identify the three basic patterns of fingerprints,
let’s learn about three career opportunities that specialize in biometrics or fingerprinting.
