At this time, high-contrast negatives were made using the wet plate collodion method (a solution of nitrocellulose in ether or acetone on glass).
æt ðɪs tˈaɪm, hˈaɪkˈɑːntɹæst nˈɛɡətˌɪvz wɜː mˌeɪd jˈuːzɪŋ ðə wˈɛt plˈeɪt kəlˈoʊdiən mˈɛθəd ɐ səlˈuːʃən ʌv nˌaɪtɹoʊsˈɛljuːlˌoʊs ɪn ˈiːθɚ ɔːɹ ˈæsɪtˌoʊn ˌɔn ɡlˈæs.