I want to spot out pinholes on my 4x5 TMax-400 negatives, and I don't mind if the result is an opaque spot that I later have to re-spot on the print. I've got a full kit of stuff to do the job with but haven't yet hit on the magic combination.

I've got an Adams Retoucher and 30x microscope. I've tried using the pinpoint steel etching tools to rough up the back and I can make it visually blend with background but the result on the print is invisible. I assume this is because I am using an Omegalite diffusion head.

I prefer to do the work on the back because I don't think I will ever be good enough to do it on the emulsion.

I just picked up a bottle of gum arabic and am going to try mixing it with New Coccine.

Any other suggestions or tips?

Thanks in advance,
Bill