Put two samples of fingerprints next to each other. Make sure each fingerprint is black ink on white paper, so that the contours of the lines can be clearly seen and analyzed.
Hold the magnifying glass over the prints about two inches from the paper. Or, at an appropriate distance so that the print is visible without being blurred.
Distinguish each of the fingerprints by looking for an "arch" shape. The "arch" is a specific type of pattern that consists of a series of upturned U-shaped lines layered on top of each other.
Compare the positioning and size of "whorl" patterns. The pattern starts with a small dot before swirling outwards, like the shape of a snail's shell. Assess the difference in the distance between the lines and the size of the swirl to differentiate between the fingerprints.
Identify "double loops" contained within each fingerprint. This is an S-shaped pattern that can be positioned at any angle. Again, check how close together and wide the lines are to tell the fingerprints apart.
Assess the dimensions of any "simple loops" you can observe on the fingerprint. The "simple loop" is a elongated U-shape that begins at one point. It is a basic fingerprint pattern to spot on a print.
Review the shapes you identified in each fingerprint to further narrow down the differences between them. Loops begin on either side of the finger and can move up or down, but finish on the opposite side of the finger, while arches point upwards, similar to mountains.
Count the number of lines contained within each fingerprint pattern. This provides a further differentiation between the prints.