Its a type of mask not for blending but say like take the tank I did, everything is still completely there but with certain ares selected thats what doesnt get masked. like if i select the tank and shiz then vector mask it in my way of rendering( which i aint gonna tell you ) then only the tank will be left.
when you use the shape tool in PhotoShop (PS) it actually creates a fill layer with the shape masking the bit you dont want. you can also handdraw a vector mask using the path tool you can use the selection of that path or shape to create a mask for another layer or imagefolder. the mask is what you use to hide/show a certain part of a graphic. you also have a normal mask, which is non-vector. imagine a grayscale image that defines the transparency of the layer it is applied to. black means it hides the underlaying pixel completely, white means it shows it completely and any gradient in between shows the pixel more or less depending on how white it is. to create a mask activate the layer you want to mask then in the layers palette click "Add New Mask" (its the small rectangle with a circle in) your colors will switch to grayscale now you can modify that mask as you would the normal image, use filters of fills. cant use styles on a mask, no point to it really. to go back to editing the normal image, click the imagelayer thumbnail in the palette, the eye will appear. to go back to editing the mask click the white rectangle to the right of the imagelayer thumbnail. the eye will be replaced by the mask symbol. another way is the use of channels, but that's not for now. Check the link to a tut in my sig
