I check in the vray properties matte shadow, and cast shadows but it keeps showing on the render. what I am missing?
Do you mean it’s still showing in GI (light and shadows casted on it?) or it’s still showing in the alpha ?
Uncheck the ‘receive GI’ checkbox, for a try.
You should use the ‘alpha contribution = -1’
You can also use a vraymtlwrapper instead (material editor). Same features there, but you’ll control multiple objects with one material (more practical)
I meant it still shows in the render is like the check matte didnt work at all.
I use the vraymatwrapper now the object doesnt show but doesnt cast shadows. I check shadows in the mat editor, also when I check matte shadow in the object properties the objects shows up in the render again but doesnt cast shadows.
I’m curious, this is working quite well (excepted shadows over itself, but it’s a common problem to many renderers)
What type of light are you using ?
If you do not find by clicking around, plz post some info about your scene. 
set the alpha contribution to -1 to remove it from the Alpha channel.. if thats what you mean
Hi I am using an omni(off) and a spot with vrayshadow, is very weird because doesnt matter what type of material I use the objects shows in the render with the gi shadows + direct shadows and the colour is allways a light gray color, the thing is that I have a diferent file with a matte shadow object and it work well. The object doesnt dissapear the way a normal matte object does is like the matte shadow is not working at all.
Ha, if there’s still some grey thingies that outline your object, these are created by GI.
So, as I asked you, uncheck “Receive GI” and have a test please. That would be a good track to begin with.
I can send you and email, no outline the whole object shows, already chek receive GI. didnot work I can send you an image and the file if you want.