Question Spray Paint Shader: Need Transparency for effect

Hi, I am updating a URP shader in 2020.2 which allows for spray painting in VR. I have the spray painting concept working. I do not know how to make the Base Color completely see through, without making the paint blobs also go invisible.

Changing the Base Color alpha appears not to help, nor does changing from Opaque to transparent (and then changing the alpha value), however I do expect that may be part of problem. The paint blobs are affected by that same alpha value, so it seems unlikely to help.





I'd be really grateful to anyone who can help. Thanks!