render layer id values

I have a scene with a beauty master layer & then 3 id matte render layers all with differently assigned R,G or B surface shaders so i can pull mattes off in nuke. But the values dont seem to be pure R,G or B . What should my color mapping settings be to retain a 100% R,G or B?

ANy ideas

Thanks

Do you have a physical camera? Is there any tone mapping happening?

yes, ! physical cam!

Got caught up a couple of time. :slight_smile:

yeah, caught out by that. sorted it! Cheers!