Acid · tarn  from the German acid " acid" and  tarnen  “camouflage.” We discovered  Acidtarn  by accident while conducting dye tests in 2017/2018. During these tests, two identical Flecktarn parkas were sent through the standard Versengtarn  dye process to confirm our dye ratios, additives, and wash procedure. When we had finished processing the parkas, one came out the black "Versengtarn" pattern we expected, and the other came out a deep iridescent green. The difference came down to the ratio of cotton and synthetic yarn. Prior to 2005, all Flecktarn uniforms were manufactured with a relatively large percentage of cotton. After 2005 this was changed, increasing the proportion of synthetic material in all German uniforms. Because our dye selectively binds to cotton, the undyed synthetic fibers created a dramatically different garment. In person Acidtarn  appears similar to an olive drab, with an iridescent "oil slick" green from the synthetic content. In fact, we considered naming it  Ölpesttarn "oil spill pattern"   for exactly that reason. In the end our informal nickname "Acidtarn" stuck, proving to be just as acceptable in German as it was in English. Each field shirt is prof