What about dry or humid finger?

Dry fingers, which are the condition of people with dry skin, produce almost always very light and uneven images, that can reduce consequently the capacity for identification. While other types of optical sensors often try to solve this problem by covering the optical drive with silicone (which is consumed quite easily), the iGuard uses technology DFX software (developed by Veridicom) to reduce the effects of this problem. To improve further the verification, the users are advised to massage with their fingers their own nose or the forehead, raising in such way the pressure of the fingers, or by using creams for their hands to minimize the problem. Wet fingers are totally a different problem and depend whether on  wet hands, from too much cream used for the hands or a skin excessively sweat. In this case the fingerprints’ ridges will be crushed and will appear to be spread on the image, or image itself will turn out to be completely black.  A Fingers’ wash and a decrease in pressure can mitigate this problem.