All of these resists certainly offer great hope as a way to “ground” copper plates but I am becoming frustrated in how poorly the consistency of use is! When I tried to cover more of my plates in resist area, I found very spotty coverage.  The plates just have random spots where the toner does not adhere. I have tried many techniques with the iron and cannot get a predictable and uniform result.  I have switched to the clamped plate “sandwich” in the oven technique also with mixed results.  

 

The toner resist does work very well in the electro etching process but I cannot achieve a consistent resist.

 

All of the forums I am reading in my research have lots of posts about similar frustrations with pnp blue.

 

The one thing that I have learned that gives me some hope for the puretch is the mechanical cleaning of the plates with 0000 steel wool.  I can see that is necessary and maybe that will help me with the puretch approach. I can get the heat consistency with the oven technique with pnp blue but I believe the pressure variations across a plate are just too much of a limiting factor.

 

If someone can claim to make 10 plates and get 8 to come out fine, I would love to talk with them!

 

So , I guess I am back to give puretch a try with the mechanical scrubbing in addition to the solvent cleaning and brightening.  Puretch will have an advantage as pressure  and subtle plate “warping” are not an issue.

 

I am going to try the “rolling” the plate over a dowel while pressing with an iron technique as well the “c-clamp the plates” in the oven technique to increase pressure.

 

I am afraid that I am coming to a hard trade-off - pnp blue yields a better resist without lifting to electro-etching but uniformity and consistency of application is not as good as puretch.