More on Pronto Plates

Pronto Plate before printing. I used Sharpie,
wax crayon and a wax wash to make the marks.

I stepped into the studio yesterday and worked on a hand drawn pronto plate. 

My steps:

• Try Sharpie, which I heard works on these plates (jury is still out on that. I didn't have much luck)
• Try litho wax crayon. (this worked)
• Make a wash out of wax crayon which has been diluted with alcohol. (this worked OK. Not the tusche I remember way back in my stone litho days. I've since read here that I should have mixed with distilled water.)
• Heat set the drawing/wash with a heat gun.

I'm still figuring things out for sure, and I'm not saying this direct-on-plate method didn't work, but I had more success with the laser printer version the other day. What's the beef? Well, in my zeal to get a nice rich black, I over inked the plate and then over wiped with my sponge, and in the process I rubbed too hard and took off some of my wax crayon despite the "setting" with the heat gun. I did learn something. Sets Well in the ink is a must. I tried the ink at first with no additives--regular etching ink, not litho ink. Easy Wipe or Sets Well is essentially a tack reducer and doesn't affect the color. It makes the ink buttery and it just glides on much better with the additive. 

One of my proofs. You can tell my inking
on the bottom was just so-so on this one.

I think if I had a grasp on the chemistry I'd have a better understanding on what's happening in the studio with the pronto plates. In an attempt to enlighten myself, I started by checking into gum arabic (yes, there's a Wikipedia page) and found

Multiple layers of gum are used ... to build up a protective barrier that ensures the ink does not fill into the whitespace of the image being printed. 

I read this too:

It is also possible to print from black and white photocopies using a 50% Gum arabic solution. This is carefully sponged onto the photocopy, and oil-based ink of any colour is rollered over the photocopy. The ink can be removed fairly easily from the white areas by carefully wiping with a damp sponge and the "paper plate" used to print using an etching press.

Essentially this is what I'm doing with the pronto plates. I'm not using a 1:1 ratio of gum arabic to water though...

If you have any experience using pronto plates and can offer any advice, please do!