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I have a vector image with multiple layers, but I want to cookie-cutter-style trim the whole image, so I'm only left with neighboring objects and no overlapping.

Here's the initial image: enter image description here

And here I'm showing what kind of objects each layer contains:

enter image description here

After I select all objects and do a pathfinder trim I get these artifacts between objects:

enter image description here

They are little dashed lines where each line is a separate closed path and they're all over the place. Is there a way I can cookie-cutter-style trim this image without those artifacts appearing?

Edited:

Here's the link to vector file: https://www.freevector.com/student-activities-on-the-school-yard-31231#

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  • Hi. Welcome to GDSE. I can't seem to replicate this problem. Perhaps it's caused by the way the shapes already abut each other in the original, possibly small gaps, etc. That's just a guess. Can I ask why you need to remove all the overlaps? Is it for vinyl cutting or something?
    – Billy Kerr
    Jun 29 at 11:04
  • I posted a link to the vector file: freevector.com/student-activities-on-the-school-yard-31231# I'm trying to create an app where the user can manipulate each induvial object. Jun 29 at 12:10
  • The artifacts have similar dimensions as other objects but their areas aren't showing up. Here's a link with an artifact and an object, they both have almost the same dimensions and fill colors without stroke, what is the difference? drive.google.com/file/d/1IF-L2DsQaNaotOhpcaCInb9PPsPFMK-z/… Jun 29 at 12:48
  • Your objects weren't well aligned before trimming. Did you check things in Outline Mode first?
    – Scott
    Jun 29 at 13:27
  • Yeah, as I suspected, it appears there are small gaps which are causing the problem. I can definitely see them if I zoom in outline mode. So the problem is specific to the artwork. I don't see why you would need to remove overlaping objects for an app to be honest. I think it would make any kind of manipulation harder, not easier, because then you'd need to alter the paths of all the adjoining shapes.
    – Billy Kerr
    Jul 1 at 9:55
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This approach of cutting out each individual vector object is almost always the wrong approach. Vector graphics are much easier to work with and visually more pleasing to look at if you allow overlaps.

Only reasons to cut out everything I can imagine right now would be if you need to physically cut out each object with something like a laser cutter or perhaps if you are making some kind of jigsaw video game.

Regard working with vector like working with colored pieces of paper. If you want a red circular piece of paper on top of a blue rectangular piece of paper would you really cut out a red circle and also cut a circular hole in the blue paper? No, it would be double the work and give a sloppy result.

Having everything cut out also makes it impossible to move object around later, so it really takes away some of the advantages of vector graphics.

100% accuracy isn't possible

Working with vector in Illustrator it might seems like you are working with absolute precision. In fact you are not. Illustrator (and all other computer programs) have a limit to how many decimals it can work with. Lots of small rounding errors and approximations occur all the time. Most of the time you don't notice this, but this particular approach really shows the limitations.

Let's look at a really simple example with just two overlapping shapes.

If we copy the top object, select both objects and use the Minus Front operation and then paste the top object in front, we can see how the hole in the bottom object is slightly deformed compared to the original object.

If we instead use the Trim operation, we get a much better result:

I assume this is because Illustrator applies the same inaccuracies to all objects in one go. I'm not sure, but I don't think this result is 100% accurate either, it's just more accurate.

If you have some complexity that forces you to perform the Trim operation several times, you will get inaccuracies similar to what we got with the Minus Front operation. It's very cumbersome to keep everything as precise as possible in complex artwork.

Display problems on screen

When displaying vector on a screen, having overlapping shapes gives nicer contours.

On the left we have overlapping shapes. On the right I have used the Trim operation. Notice how there are subtle bright edges on the image to the right. These are called conflation artifacts.

Trapping problems on print

When printing vector, trapping is applied to avoid white gaps between shapes. Lighter inks extend a tiny bit into darker inks to create an overlap that accounts for misalignment.

On the left we again have overlapping shapes and the trapping works as expected. On the right there is a hole in the purple shape, which isn't exactly the same shape as the red shape. So the trapping is only applied where the shapes actually touch each other. The trapping looks a bit fragmented and it might be noticeable on print.

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  • Thank you for the in-depth explanation, I feel like I understand my problem better now. I'm actually designing something very similar to a jigsaw scenario, so that is why I need cookie cutter style trimming, I'm going to be manipulating each object and any overlap will cause problems. Jul 6 at 23:46
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It is all on the way you approach the vector trim work. It happened a lot when I started using Illustrator, after using Corel for over 15 years. Rather than trimming a good process I recommend is to set all your art in correct position back or forward and then use merge. Be aware that objects that overprint will not trim back objects. Same with the attribute multiply. Most of all avoid trim more than once. Hope that helped somehow. :)

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    This may or may not be very good thing tp do though. As conflation artefacts are coused by just this workflow
    – joojaa
    Jun 29 at 13:29
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    Overlaps can actually be a good thing.
    – Scott
    Jun 29 at 14:00

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