Hi,
I have a certain material I am working with and I would like to overlay some eyes I drew in photoshop on the model. I am just having trouble where to put the image texture without altering the texture color or completely covering the material.
Any advice to go about accomplishing this would be very much appreciated. 
And below is my blender file in case that is needed.
kathy_hm_cycles.blend (663 KB)
Am I correct in understanding you want reflective eyes? Or if not, what effect exactly are you looking for.
Possibly use the technique I am showing in the “Grunge Control Node” thread in this forum. Not sure if it will help, but it shows how to overlay a .png grunge texture map over top of an existing texture (using 2 UV maps) without disrupting the original texture. You may need to set the overlay type as “add” instead of “multiply” as I have it shown. Good luck
If you want the eyes overlaying but the base material still visible where the eyes are not, I am presuming you need an alpha channel on your eyes texture to control the mix. You use the same sort of thing when applying reflection maps etc.
