This research includes the study of the effect of zirconia (ZrO2) additionin a different weight percentages (5. 10. 15. 20)% to porcelain samples formedfrom (Duekhla Kaolin. https://www.spidertattooz.com/OPI-GelColor-The-Color-That-Keeps-On-Giving-0-5-oz-HPJ07-p22791/