Adobe Illustrator to Inkscape: clipping paths and masks

inkscape
adobeillustrator
clippingpaths

#1

Continuing the discussion from From Illustrator to Inkscape to Glowforge: eight cats!:

At this point in time the Glowforge workspace displays an error message about clipping paths if there is one in the design file. So far it hasn’t affected how to do the print settings or arrange the objects. But I couldn’t let it go so I spent some time trying to figure out the source of the clipping paths that appear in the files that have been done in Illustrator and converted to a PDF or SVG.

I’d appreciate any comments, suggestions or explanations about this phenomenon. One hopes that the Glowforge interface will process Illustrator files natively, but there still might be aspects of the design that might not work. For instance, Ponoko requires that files submitted for processing not contain cllipping paths.

This isn’t to call attention to deficiencies in the Glowforge, Illustrator, Inkscape, @cynd11’s designs but to understand more completely some crucial aspects of vector design that can figure into the workflow.

It started with trying to figure out the source of the clipping mask in the eight cat design file that was a PDF.

I worked with @cynd11 to trace down what was contained in the design files that weren’t apparently visible. I asked @cynd11 to send me a file with some simple squares and circles to see what would happen. She sent me the AI and I opened it up in Inkscape and without changing anything, saved it as an SVG.

The Glowforge interface indicates that there is a clip path in the AI file that I saved as an SVG.

The file looked like only three empty squares and three empty circles. In fact, they were imported as two sets of circles and one set of squares. Part of this is the clip path problem. Part of it is the white fill that was in the circles, which is what we want if we want to engrave something.

Here is the image opened in Inkscape. Note that the squares are behind the circles and there is no transparency.

The circles are actually filled white, not sure if that’s what was intended and the circles were filled to start with. Maybe that’s where it originates.

If I right click on the objects, it doesn’t appear to be any clip path/mask.

But if I remove the fill on the circles, they still aren’t transparent. Evidently there is a mask on those circles.

I selected everything and noted that the original location of the circles still contained a clip mask. Note the selection squares around what looks like blank space:

In fact, there are still circles there. I put a red stroke to them to show them. I also ungrouped them.

I deleted the extra circles, then I selected everything and converted the strokes to paths. Broke them apart, deleted the extra shapes that now filled the squares and circles and then tried to import to see if any clip path was present.

Still get the error message, but now I have three simple circles and three simple squares in one operation in the Glowforge workspace.

I’ve selected them all again, released both the clip and the mask (even though there was no indication that there is one anywhere in the document and I still get the message that there is a clip path.

So then I copied the squares and the circles and pasted them into a new document and imported that into the workspace. No clip path warning. Strange.

So then I tried to import an empty document with all the circles and squares deleted. The Glowforge workspace says there is nothing in the design and gave an error.

So then I took the original document that had all the circles and squares deleted and then put in one square that I made into a simple stroke. Clip path error upon opening in UI.

Arg!!! So what is in this document that does it? I’m going to keep poking around. So for the first time, I used the XML editor in Inkscape to look at the file contents. There was a clipping path somewhere. I still am not sure how to access it or delete it from the normal Inkscape workspace.

So that’s where it stands.

Once again, I was able to use the file that @cynd11 sent as it was, but in the interest of understanding the design process and all the elements of vector files, this has helped me.


What is This Clip-Paths Error?
#2

THANKS for your ongoing insights!


#3

I wonder if the clip mask is created/a function of how Inkscape “opens” an AI file. Because AI is a proprietary format of Adobe, Inkscape must be converting to its own “version” of AI in order to display it. Illustrator does have the ability to save as an SVG (File/Save As)…

I wonder if the mystery clip mask exists that you’re experiencing still happens if you start with an SVG created by Illustrator?


#4

Yes, that is a great point to make. Thanks for reminding me. @cynd11 sent me an SVG that was output by Illustrator. It opened without the clip-path error, only three circles and three squares, no fill. I had forgotten to test that file once I went down the rabbit hole.

So that does indicate that it is how Inkscape processes the AI file in an SVG.


#5

I would suggest saving the PDF at another setting. Maybe high quality printing.

When I look at a default setting PDF in text edit it shows bounding box information.

The high quality printing PDF does not.

Just an observation :flushed:


#6

I have so much to learn


#7

A couple questions, not too informed:

Is this anything about how Inkscape handles any of AI’s metadata?
Or about Inkscape svg versus the real kind?


#8

I think the answer is yes.

I thought Inkscape output a truer SVG, an AI had the bastardized version. Have I had it backwards all this time?


#9

Inkscape’s default version of SVG is an Inkscape-modified version. That’s why there’s a SaveAs option to save it in a standard SVG.

It’s still likely though that AI’s version may not be entirely true to the definition either, but that’s the nature of supporting interchange files.


#10

Basic question about all of this … is there a specific glowforge related reason for using Inkscape over Illustrator or is it that Inkscape is free?

Thanks
ez


#11

Inkscape is free. :smile:


#12

Yes. It’s free. It’s open source and there is very active development too. Lots of nifty extensions.


#13

I’ve been frustrated by this too - definitely something @Tony has in the hopper.

If memory serves, PDFs have a clipping path around the page border - I think to constrain what’s shown to only what fits on the page. That’s the bit you have to find and release.


#14

Adding my question here, to this very old post. I searched on the forum and saw Marion’s post about clipping paths, read it all, and decided to ask here. I also searched online for a definition of clipping paths. I also recently experienced the error for clipping paths when I got ready to print something. At the time, my way around it was to set it to ‘ignore’ that step, which worked for me. Even though we’re all using different software for designing (I use AD), I’m thinking that the term clipping path is pretty universal. Will someone please give me an easy to understand definition of the term? What I found online would confound even the most versed person. What does clipping mean ? And what does path mean? And all together…what does it mean? Please and thank you.


Weekly Highlights for the Week Ending May 6th, 2017
#15

I’ll try.

A clipping path is generally a border around an image that is used to hide surrounding background. The clipping path lets you see only what you want to see. The problem a that the rest of the image is still there but it’s not visible, it’s just been masked out.

That would be the part that annoys the GFUI but I’m guessing since I don’t have a PRU to play with.


#16

Exactly right. It didn’t change the ACTUAL drawing, just what is visible (figure it is a cutout piece of paper, you can’t see what’s outside the hole, but it’s still there. That is different than if you take that clipping path and do a boolean operation (via Pathfinder in illustrator) where you truly eliminate inside or outside that path forming a new image.


#17

I don’t know about @Xabbess, but I just can’t picture what you are trying to describe. It sounds great, and I’m sure it actually makes sense. But I’m not getting the “lightbulb moment” of understanding on this one.

Would it make sense to request an graphic of what you are describing? with arrows and such?


#18

Ask and ye shall receive:


#19

I moved away from the computer for a couple minutes so you beat me. :grinning: Excellent example.


#20

haha. I sometimes feel that the forums operate more like a Slack channel rather than a typical forum, given the rapidity of posts back and forth…