Help needed: Overprinting for three colors

yes in essence you ar right. If you are using 4 colour process inks they are transparent inks to start with. So yellow and cyan will give you a green. To vary the green you either need to vary one or other of the colours by use of a screen on the plate or the amount of ink laid down. magenta and cyan will give you blue to purples, yellow and magenta will give you reds to oranges. Have fun!! Look up the Jean Berte Process, this was patented in the USA back in 20’s using water based inks giving some wonderful art nouveau poster type productions.
On Drying times, give the ink enough time to dry so that you can handle it for the second print, but dont leave it for days as the second colour might not take onto the first.

I agree with Frank above. If you are using process inks (cyan, magenta, yellow, black), they are transparent so you don’t have to add trans white to them. You are basically printing colored filters on the sheet. In your example above, you will get the most pure emerald green if you don’t add trans white. If you want to get a more yellowish green, or a more bluish green, or a weaker green, then you can add trans white.

Frank is right about drying too. Let the ink dry to the touch but not too long.

Also, inks will adhere to the paper better than they will adhere to each other. So, if you have one color that covers a lot more of the paper than the other color does, print the one which covers more of the paper first.

I have a related but different issue than Nate regarding multiple colors in a print. I am not looking to combine two colors to make a third. But I do want to overlay colors - one atop another - on the print. The advice about not letting the ink totally dry before the second color is applied would be a problem for me. I will be printing several copies of a poster (175 or so) on a hand press and would not be able to finish the complete run of a color in a single day. Is there a process I can use that will assure the second and third layers of ink will stick on the layers below?

I understand the advantage of printing the color covering the largest area first as you are combining colors. But if I am not combining colors, but want to overlay colors, my thought would be to print the lightest color first followed by a darker color regardless of the area being covered. Is that the more correct way in my situation?

John

If you are overprinting wet, I think you want to reduce the tack of the ink for each successive layer.

There could be a significant change in color by overprinting two colors in different order. You can get some idea of the effect (but not exact) by doing “drawdowns” of the ink you intend to use in the various combinations.

Better yet, just hand ink and do a proof of the colors you intend to use. If you don’t have a press handy, you can just do a proof by inking a block and rubbing the paper over it as some lino cut artists do.

No one here on this list can answer your questions fully without knowing exactly what inks you have to hand. The best bet is a trial proof or drawdown.

John Henry
Cedar Creek Press

UPDATE: So it looks like I may not have process color inks.

Here’s what I’m using:
• Vanson Rubber Base Plus Pantone Yellow
• Southern Ink Process Cyan

Is the green overprinting effect going to be possible with these?

Great info so far, everyone. Thanks for the help!

Looks to me like your cyan is process… I don’t know about the yellow.

I would try overprinting Cyan on to the yellow. The other direction might or might not work.

Try it and see.

Yellow isn’t always so visible as the first pass. Looking at it through a blue glass or filter can help.

Back in the good old days when printing 4 colour illustrations, yellow was the first colour down followed by magenta. As the day went on the ink would get thinner and it was quite easy to run light on the yellow so we changed and started printing the magenta first as magenta was easier to control.

natehofer Pantone yellow will probably be pretty transparent, but to test it, roll it or print it on some black paper. If you can hardly see the yellow, it is pretty transparent. If you can see the yellow plainly, then it may be more opaque and might hide other colors unless you are putting it first down. If you don’t have any black paper, look for a black printed area in a magazine and use that.

jnbirdhouse: the problem you can get into with inks not adhering to each other when they have dried, is that some inks have wax in them. This is not wax as we think of it like candle wax, but very fine powdered wax like polyethylene wax. Over time, this wax “blooms” to the surface of the ink film and forms a protective layer on top of it. It makes the ink more rub resistant, and that is why the ink makers put it in the ink. The problem with the wax layer is that another layer of ink printed on top of it, will not adhere to it very well, if at all.

The safest course of action would be to 1) make a test, simulating the time intervals you would be having between colors. 2) Another good thing to do would be to ask the ink maker who made your ink, if there is wax in it, and if overprinting can be done, and whether the time between the printing of the different colors should be restricted.

Most ink makers are happy to help because they want you to be successful and like their ink and buy more of it.