ðə faʊndˈeɪʃən ʌv ðɪs mˈɛθəd ɪz ðɪ ɪnsˌɑːljuːbˈɪlᵻɾi ʌv baɪkɹˈoʊmeɪt ʌv pˈɑːɾæʃ əpˌɑːn ɛkspˈoʊʒɚ tə lˈaɪt, ɐlˈaʊɪŋ ðə pɹˈɪntɪŋ ʌv ˈɪmɪdʒᵻz ˌɑːntʊ zˈɪŋk fɹʌm fˌoʊɾəɡɹˈæfɪk nˈɛɡətˌɪvz.
The foundation of this method is the insolubility of bichromate of potash upon exposure to light, allowing the printing of images onto zinc from photographic negatives.