This paper investigates the effects of coating such as Invar (Fe-36% Ni), Fe-Ni Alloys and $WO_3$ on the doming property of aluminum killed (AK) shadow masks, which may be used for flat CPTs. Invar and Fe-Ni Alloys are deposited on AK shadow mask in plasma atmosphere and annealed. $WO_3$ is screen-printed on the deposited layer. The coating is observed to cause a decrease in the doming property of the shadow masks due to their lower thermal expansion coefficients and anti-doming properties.