More Magic Metallised Paper Experiments

I've been trying to make paper that works in the Casio FP-10 printer. See the previous post for attempts one to six:


 https://trochilidae.blogspot.com/2019/12/magic-metal-paper-in-seventies-casio.html

Attempt Seven 

 Spot weld primer.

Anyway, I was watching an episode of Wheeler Dealers and Edd mentioned that you use a conductive spray primer before you spot weld, sometimes. That was interesting as I had been looking for conductive spray paint. A quick google and it appeared that yes, this primer was indeed conductive due to either zinc or copper in the spray. Not only that but it as available at a local auto supply shop.
One trip to the shop later and I had a can of pretty expensive zinc spray paint. It was no problem to then spray a sheet of A4 paper:

When dry the surface is similar to the magic paper, and even shines up a bit if you rub the surface:

Unfortunately, even though I did measure some conductivity when drying, the paint seemed to not be conductive when dry. I did a couple of sheets with varying numbers of layers and ran some test strips through the printer:

As you can see, it's a bit messy and clogged the print head as the final product is quite thick. It also didn't work.

Attempt 6b

I then had an idea about testing the paper. I set up a PSU with 15V on it and attached one wire to the paper then dragged the other wire across the paper. This gave me an idea whether the paper would spark erode or not. The real Casio paper worked fine (as expected), but the only paper from my tests that worked was the 'gilded' aluminium one. Here's some scribbles I made, which are spark eroded. The black you can see is some paint I sprayed under the aluminium, just like the real paper.

Even though this manual test worked, it didn't print in the FP-10.