for the dimentions we can fill the backgroud it can wipeout it is like wipeout cammand can we do the same for text the mask command can only fil with color , i need to fil it with wipeout so i can hide everything comes beneath it thx.

I believe you said "mask" only works with color. If you are referring to masking of "mtext", you can have a color background or a "wipeout" background.
 
In options for "background mask" check the "use drawing background color".