Iseyile yomthunzi yahlulwe yaba yiseyile yomthunzi ophefumlayo kunye neseyile yomthunzi ongenamanzi.
Iseyile yomthunzi ophefumlayo yenziwe ngepolyethylene exineneyo kakhulu enokuthintela imitha yelanga ye-UV eyingozi, kodwa iphinde inciphise kakhulu iqondo lobushushu ngaphantsi.