according to an interview with Bill Jordan, from Spartan-Realtree and Jim Crumley, from Trebark fabrics there are no optical brightners in any of the ink dyes or fabrics used in their clothing at all. including all cotton/poly blends.

also another interview with John Coulbourn, President of Coulbourn Instruments/Megabucks Trophy Nutritional Products, who holds a degree in Behavioral Psycology and Zoology who has completed extensive studies regarding vision in animals. states "Mammals (in fact, most vertebrates) which have color sensitivity are similar to humans; and any deviations from our green centered sensitivity tend to be to the far red, the opposite end of the spectrum from violet."

there is no viable and conclusive evidence that deer or any other mammal react to ultra violet light reflected from camo clothing and its effect on hunting. many researchers and scientist say that animals eyes react to movement not color when fleeing from a predator.

from my experience i have never used any detergent to take away the ultrviolet brightners,i have just to take away scent. i have seen and harvested many deer in the last 20 years and never had a problem with my camo.