Hanyar simintin gyare-gyare ta sami hanyar yin simintin gyare-gyare daban-daban a cikin abubuwan filastik na ƙarfe, wato na narkewa, fita, da bugun ƙarfen ruwa a ciki, ko wata hanyar yin simintin gaba da aka yi wa abokiyar allurar riga-kafi, za a sanyaya polishing bayan hanyoyin injiniya kamar samu da wani nau'i, girman da aiki.