Pixelate>color halftone>reverse dots

[Debra Lynn]

I have relentlessly tried to convert a grayscale image to a pixelated rendering and it worked fine in rgb mode, but when converting the file to cmyk the dots took on a negative aspect. I took the following steps:

1. Import grayscale image
2. Effects>pixelate
3. Pixelated object and second color box to create opacity mask.
4. Invert mask.

Everything looked great until converted to cmyk when the halftone screen was inverted so that the dots become white with my color going into the negative space.

I realize that I can create the same effect in PS, but I assume the image would have the jaggies. I am totally at a loss and would certainly appreciate any assistance. Ignorance is such a beast.

[John Kallios]

I am using 10.0.3

On a grayscale image, I can use effects pixelate in both cmyk and rgb mode.

You lost me with step 3, were you using opacity mask to colourize the image to a swatch colour?

I followed your steps starting in rgb and I cannot reproduce the problem. Like I said, I can also bypass the rgb step and stay in cmyk mode.

John

[Debra Lynn]

John, thanks for your response. I am using Ill 9 by the way. Step 3 was just the task of grouping the pixelate image with a color box so that the dots of the image could reflect the pantone color. I tried it several times last night using the same steps and each time the rgb file reproduced just fine. But when I converted the image to cmyk the dots kept reversing to white. Is there anything in the transparency palette that should be switched off or on. I kept toggling the buttons but to no avail.

I did also start initially with a cmyk file and followed the same steps only to have the same disasterous results. Would appreciate any additional input.

[John Kallios]

When you mean convert to cmyk. Are you talking about the colour mode or are you rasterizing the image to cmyk?

So I have a clear understanding of step 3: Your image is grayscale. You create a fill with a spot colour (say pms 185) the same size directly in back of the image. You select both and apply inverted clipped opacity mask. You then are left with an monotone pms 185 image?

Can you send me a sample graphic showing before and after. I am running 10 but I will probaly have a helpful suggestion upon seeing the file.

uni...@pacbell.net
or
john2orionprinting.com

John

[Debra Lynn]

John,
I finally re-installed Illustrator and the cmyk files with the halftone pixelation with positive "dots" has started to kick in. I suspect that perhaps the conversion from rgb to cmyk may have had a reprecusion or the six separate files had been corrupted. The placed files were in gray scale with the colored box behind when creating the opacity mask. Thank you so much for your assistance.

[Debra Lynn]

[John Kallios]

I am glad it worked out for you

John