ɐn ɛksˈɛpʃən ɪz ɐ tˈɪɹ ɐlˈɔŋ ɐ pˈɜːfɚɹˌeɪɾᵻd lˈaɪn, æz fˈaʊnd ˌɔn ɐ ɹˈoʊl ʌv tˈɔɪlɪt pˈeɪpɚ ɔːɹ pˈeɪpɚ tˈaʊəlz, wˌɪtʃ hˈæzbiːn pɹˈiːviəsli pˈɑːɹʃəli kˈʌt, sˌoʊ ðɪ ˈɛfɚt ʌv tˈɛɹɪŋ wɪl pɹˈɑːbəbli pɹədˈuːs ɐ stɹˈeɪt lˈaɪn.
An exception is a tear along a perforated line, as found on a roll of toilet paper or paper towels, which has been previously partially cut, so the effort of tearing will probably produce a straight line.