Fingerprint Facts

Why do people leave fingerprints.

The sweat glands in the skin of your finger tips produce a water based oil solution that coats the ridges of your print. These ridges retain a portion of this solution such that when the finger makes contact with a surface, a residue is left behind which is a facsimile of your print (i.e., laten print). It is this characteristic which gives Sense Technologies Inc.™ biometric devices the ability to electronically scan and analyze your print

Common Types of Fingerprints

Fingerprint patterns are divided into three main groups consisting of: Arches, Loops and Whorls. Approximately five percent of all fingerprints are Arches, 30% are Whorls and 65% are Loops.





Good Prints

Fingerprint scan quality can affect the reliability of any electronic fingerprint system. In general, automated fingerprint analysis systems work by creating a computer model of the live print scan. This model is based on many of the features found to be common in fingerprints and is sometimes referred to as a template. The process of creating this model/template is usually referred to as a 'Registration' process.

The process of matching a live print scan to a model/template is generally referred to as a 'Lookup'. The following are examples of GOOD print scans.

NOTE: CheckPrint T/A creates a computer model of your print which can only be used to verify against another live-scan of your print. It is not a facsimile nor can it under any circumstances be used to re-create a facsimile of your print.


Dry Prints

Due to a lack of natural moisture in the skin, a dry print can appear broken or incomplete to the electronic imaging system. This can result in inferior model construction during a registration process or inconsistent matching during a look-up process.

Dry skin can be caused by a multitude of climatic and environmental conditions. Handling materials or substances tend to absorb or wash the oils from the print. Items such as paper, cloth, wood or chemicals (i.e., acetones, thinners, cleaning agents etc.) will have a direct result on the dryness of your fingers. These items tend to absorb or wash oils from the skin leaving the ridges void of the necessary moisture to reliably electronically image the print.

To regenerate these natural oils, the tips of your fingers can be rubbed together or against the palm of your hand. In most climatic and environmental conditions the bridge of your nose and forehead tend to retain their natural oil.


Wet Prints

Excessive moisture in the skin can cause line-type features in the print to blend together during the registration or look-up process resulting in inferior model constructs or inconsistend look-ups. An excessively wet print is analogous to viewing a painting after a puddle of paint has been poured on it (you can't see the features through the puddle). Excessive moisture is generally caused by sweating or handling wet materials or substances. Common sources are greasy foods (i.e., french fries), hand lotion or makeup. The condition is easily solved by removing the excess moisture.


Common Line Types (Shapes)
 Found in Fingerprints
Fingerprint patterns are made up of 'line-types' (shapes) which determine the general classification characteristics of the print (i.e., Arch, Loop or Whorl). The 'Pattern Area', is a term used to describe the center area of a print which contains many of the line-types previously described. This area and its contents determine the classification of the print (i.e., Arch, Loop, Whorl, etc.). The following examples are typical of the most common line-types found in prints.


ROD-A Rod generally forms a straight line. It has little to no recurve features and tends to be found in the center of the fingerprint's pattern area.


ELLIPSE-An Ellipse is a circular or oval shaped line-type which is generally found in the center of Whorl patterns.


SPIRAL-A Spiral line-type spirals out from the center of the fingerprint and is generally found in Whorl print patterns.


BIFURCATION-Is the intersection of two or more line-types which converge or diverge.


TENTED ARCH-Resembles a tent. This line-type quickly rises and falls at a steep angle. They tend to be associated with Tented Arch pattern prints.


LOOP-A Loop is a recurve line-type that enters and leaves from the same side of the fingerprint.


ISLAND-An Island is a line-type which stands alone. (i.e., does not touch another line-type and is totally contained in the pattern area of interest.)


SWEAT GLAND-The finger contains many sweat glands. The moisture and oils they produce actually allow the fingerprint to be electronically imaged.


MINUTIAE POINTS-Is the term used to define common micro features in a finger print. Common minutiae points are the intersection of Bifurcations, ending points of Islands and the center point of the sweat glands.

-Arch line-types can be found in most print patterns. Fingerprints made up primarily of Arches are sometimes classified as Arch prints.

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