'No Mystery 2,4-D + 2,4,5-T Are Killers', poster designed and printed by Jillian Gibb (1945 ? 2017), later known as Viva Jillian Gibb. Gibb was known for her immediate response to the news. 2,4-D and 2,4,5-T are phenoxyacid herbicides, which were widely used in agricultural industries until being phased out from the late 1970s due to toxicity concerns. Screenprint on paper, 70.5 x 51.5 cm