Excerpts of an image didn't print the same as the main image

[artifacture]

Mimaki JFX200-2513 EX
Rasterlink 6
Adobe Illustrator and Photoshop current version

I've got a WebP image provided by a client. It's sRGB. It's a photo of an collage art piece composed of individually painted wood pieces. The client wants us to print and then cut out the individual pieces and glue them to a print of the full image to add depth in (licensed) reproductions.

In my original version, I used one compound path composed of all the separate pieces as a clipping mask. Both the background layer and the layer with the pieces printed fine. However, there is a lot of wasted material in between the pieces. So I looked for ways to cut up the image using AI. I found I can draw a bunch of artboards, one surrounding each piece I want. Then using the export function and checking "use artboards", it creates an image for each artboard. Then I imported those images and clipped each one separately. This allows me to nest the pieces closer together. All seems fine. If I take one of the individual pieces and drag it onto the large background image, it's a perfect match. But when I printed it, many (or all?) of the individual elements came out color shifted, lighter, kind of washed out compared to the full image.

I've confirmed opacity and blending modes are not a factor. I've opened some of the individual image part files and the main one in photoshop and in OSX Preview app which shows the color profile in use. They all have the same color mode (RGB) and colorspace (sRGB IEC61966-2.1).

I'm stumped... any ideas?

 

[DarkerKat]

What settings & file type are you using when you export the individual artboards? Any way you can post a photo of the color shifted prints? (I imagine since its licensed art that you can't post the files, but this is likely in the export settings)

 

[bob]

When an image is run through an RIP every pixel can have some effect on any other pixel or merely the presence or absence of a pixel. These pixel to pixel effects are minuscule but the are cumulative. You're sending different images, don't be surprised if they come out differently.

 

[artifacture]

The first image is the cut part next to the background and it's spot on. The second one is another of the same fruit, but the leaves are totally different. That's the other strange thing, some of it is fine, some of it is not.

 

[JBurton]

So, I'm unfamiliar with illustrator, so I don't follow what you mean exactly with artboards, but are you saying you generated a slew of files, then brought those into the RIP to nest at that point?
I'd try to nest them in my graphics software, then have all of them on the same pdf to RIP, mostly because I can't stand the way my old onyx nests things.

 

[artifacture]

Basically, it's image slicing. You can draw in slices and export them as images (intended for building websites). Or, since many of mine were overlapping, I found that I could draw a bunch of artboards ("pages" basically) and do it that way. For example, if I have an 8"x8" artboard and I lay a 10x12" image over it and then export as an image, while checking the "use artboards" setting, it will output an 8x8" image composed of the part of the image that fell inside the artboard. I did the same thing, but with 41 pieces. The screenshot here shows the piece I cutout on the right, and that part of the main image on the left. This is one of the pieces that printed off color, the one in the photo above.

 

[JBurton]

Yeah, I'd wager it's something to do with the export settings for your artboard.
Corel has a similar feature, publish to pdf, that has it's own set of settings that can potentially muck up a file.
Upload your files for the one that printed correctly and the once that did not if you want some folks to dig deeper into any differences.

 

[unclebun]

If I were doing this I'd have made vector shapes of the various cutouts, used the Corel Draw tool called power clipping to clip duplicates of the photo into them, and then exported those power clips to print and cut the exact same way I exported the original photo. Then everything would have had the same profiles when exported and they would all print the same. I don't know what it's called in Illustrator, but it has the same tool.

 

[Ronny Axelsson]

Just guessing here but I wonder if the rendering intent could have something to do with it?
If you use Colorimetric rendering intent, out-of-gamut colors will be shifted to the closest reproducible color while colors inside the gamut will be left as is.
If you instead choose Perceptual rendering intent, it will preserve the visual relationship between the colors by shrinking the entire color space to fit inside gamut.
Not sure exactly how it works but maybe the individual image slices contain different levels of colors that need to be shifted or truncated, and that this will affect the slices to various degrees.
Let's say you have a bright orange that is impossible to reproduce and that the entire slice needs to be truncated to make it fit inside the color gamut, then I guess this would change more than just the orange, at least with Perceptual rendering intent.

What happens if you nest all the pieces together in Illustrator first, and then export all of them as one single print file?

 

[DarkerKat]

while checking the "use artboards" setting, it will output an 8x8" image composed of the part of the image that fell inside the artboard.

Ok, but what settings did you select when you exported the artboards? Because that's going to impact the print since you're exporting to image.
Example below - big artboard, I want to print some sections of this image separately so I add little artboards that are overlapping the big one.
If I then export to image and select use artboards I have to confirm the image settings. (just using filler settings to show what can go wrong)
They may look fine when exported but depending on your export settings it can mess with color and resolution.

You can use that multi-artboard technique, but don't export them as images, save the file with all your artboards as a PDF and split up the pages, then follow the same process you did before- this will mean that all the chunks are still referencing that original image file, not making new ones where the resolution and color space has a chance to change. This is how we setup overlapping vinyl panels for complex graphics (that can't be broken up in the rip for one reason or another)

 

[artifacture]

I used WebP so mine looks a bit different. I like the PDF option though. I will explore that further. It's still a clip of the full image each time, but it's a reference to the image, so it shouldn't be a big deal.

 

[Solventinkjet]

I would try upping the resolution on your export settings. I'm willing to bet the original image has a higher ppi than 72 and by making it 72, you're downsampling which can cause color changes.

 

[artifacture]

No, the original is actually 72, which isn't ideal, but it is what it is.