halftoning a 2 spot gradient, illustrator > rip

[colinpatrick.charles]

After very much gentle banging of head against wall, I'm hoping the wise people here can tell me the simple small thing I'm missing to make this work.

To use an example: I have a square, with red on the left fading into blue on the right. Now I need to make 2 films to print it. When I do this the results are always the same, regardless of the technique I try - the halftones overlap (either partially or completely, depending on the angles), leaving negative space between them. I need the two spot color halftones to interlock completely.

I've tried using overprint fills, making half the gradient transparent, changing angles, all without luck.

I can make it happen in photoshop with bitmapping, but would prefer to remain within illustrator if possible. Any ideas?

[Andymac]

I'm no designer, but wouldn't you get the effect you want by making one gradient, save it, then take it and make a negative of it, and save that?

[Barry Obama]

yep

[Andymac]

go change your spark plugs

[Mark McCormick]

I'm no designer, but wouldn't you get the effect you want by making one gradient, save it, then take it and make a negative of it, and save that?

in photoshop, yes.

i don't think you can do it from illustrator because the gradients are smooth. you have to RIP the file to a printer to get the halftones. the only way i can think of is thru some setting in the RIP software if that is even possible. but i'm not sure...

[RichieGoodtimes]

Banging your head against the wall is pointless when what you should be doing is screaming at the computer.

[Andymac]

Like I said, I'm no designer. Are you saying that Illustrator won't let you create a negative and a positive? so elementary to graphics. Me, i would make a square out of rubylith, and print a nice blend. 1 film, 2 minutes to make, 1 screen, 1 pass. No halftones, no moire, no problem.

[Mark McCormick]

you can make a gradient from positive to negative and reverse it, but the gradient is smooth. the halftones are created from the printer rip software and they will overlap instead of fitting back together like a puzzle.

[colinpatrick.charles]

Thanks everyone for being so quick out the gate. Yes, forgot to mention that the tail end of this process is the rip driver (xante).

Andy, all you'd see in illustrator is the vector object, no halftones. So direct manipulation of ht not possible. Halftone business happens once the file has left illustrator and is en route to the printer, so this would be a setting in illustrator to communicate with the printer settings or printer based entirely, I reckon.

[colinpatrick.charles]

mark mccormick, yes exactly.