ðɪ ˈæp fˈoːɹɾi wˈʌn pɹˈɑːsɛs ɪz ɐn ˈɑːbsəlˌiːt kˈʌlɚ ɹᵻvˈɜːsəl pɹˈɑːsɛs jˈuːzd dʒˈɛnɚɹəli ʌntˈɪl nˈaɪntiːnhˈʌndɹɪd ˈeɪɾi θɹˈiː fɔːɹ fˌoʊɾəɡɹˈæfɪk fˈɪlmz sˈʌtʃ ɐz ˈæɡfə sˌiːtˈiː ˈeɪtiːn.
The Ap-41 process is an obsolete colour reversal process used generally until 1983 for photographic films such as Agfa CT18.