, ▁which ▁was ▁used ▁by ▁pot ters ▁as ▁recently ▁as ▁the ▁eigh teenth ▁century . ▁ ▁This ▁body ▁material ▁and ▁the ▁new ▁gla ze ▁offered ▁the ▁pot ter ▁a ▁greater ▁handling ▁and ▁manip ulation ▁ability . ▁ ▁This ▁allows ▁the ▁pot ter ▁to ▁improve ▁the ▁quality ▁and ▁appearance ▁of ▁the ▁vessel , ▁including ▁more ▁ref ined ▁decor ative ▁designs ▁and ▁patterns . ▁The ▁result ▁was ▁a ▁substantial ▁variety ▁of ▁products ▁such ▁as ▁bow ls ▁of ▁different ▁size ▁and ▁shapes , ▁jug s , ▁inc ense ▁burn ers , ▁l amps , ▁cand l est icks , ▁t ray s , ▁t iles ▁and ▁so ▁on . ▁ ▁These ▁advantages ▁also ▁allowed ▁greater ▁control ▁of ▁car ved ▁decor ation , ▁the ▁use ▁of ▁which ▁the ▁Sel ju ks ▁ref ined ▁and ▁extended ▁during ▁the ▁tw elf th ▁century . ▁ ▁Car ved ▁decor ation ▁in ▁cer am ics , ▁s gra ff ito , ▁is ▁an ▁old ▁tradition ▁used ▁in ▁nin th - century ▁Islam ic ▁pot tery ; ▁it ▁is ▁an ▁eng ra ving ▁technique ▁based ▁on ▁in cis ing ▁the ▁design ▁with ▁a ▁sharp ▁tool ▁through ▁a ▁white ▁s lip ▁to ▁reve al ▁the ▁red ▁ear then ware ▁body . ▁The ▁vessel ▁is ▁then ▁co ated ▁with ▁gla ze . ▁ ▁The ▁Sel ju ks ▁also ▁developed ▁the ▁so - called ▁sil hou ette ▁war es ▁which ▁are ▁distinguished ▁by ▁their ▁black ▁background . ▁ ▁These ▁are ▁produced ▁by ▁a ▁technique ▁which ▁consists ▁of ▁co ating ▁the ▁white ▁f rit ware ▁body