haʊˈɛvɚɹ ˌoʊvɚ ðə sˈɛkənd hˈæf ʌvðə twˈɛntiəθ sˈɛntʃɚɹi, sɪnθˈɛɾɪk ɡlˈuː hɐz bɪkˌʌm lˈɛs ɛkspˈɛnsɪv, mˈoːɹ kənsˈɪstənt fɹʌm bˈɑːɾəl tə bˈɑːɾəl, ænd lˈæsts lˈɔŋɡɚ.
However over the second half of the 20th century, synthetic glue has become less expensive, more consistent from bottle to bottle, and lasts longer.