Adobe Illustrator compatible EPS

[msdobrescu]

Hi,

During my various research on how to use Inkscape to export some EPS that keeps its vector format after its import to Illustrator, as needed by third parties, I've found that the last open specifications were for EPS v7 format. There, gradients could be exported to illustrator in its format embedded into the EPS (meaning it does parse the "pure" EPS vector, but it generates a raster out of it, so Illustrator needs some particular data specific to it in order to be able to import a real vector out of the EPS file).

Luckily, somebody did some Inkscape file type extension that is able to export based on Illustrator 7 EPS file specifications here: http://primandras.hu/inkscape-ai-compatible-eps-exporter/

This would be useful to be implemented in Inkscape "natively", IMHO.

Anyway, Illustrator's gradient meshes were available from v8 and there is no specification published by Adobe regarding data needed to be added to the EPS file in order to handle correctly an EPS file produced by another application. I have tested a nightly build of Inkscape 0.92, so I could say that Illustrator could import Inkscape's EPS, but, again, the gradient mesh is rasterized. I can't say how accurate this might be, as I did not test thoroughly, but looks OK for what I've tested. Too bad there is no public information on this matter too...

[brynn]

Welcome!

Mmm, this subject is a bit over my head, but I'll try and find some info for you.  The best place to ask this is probably on one of the mailing lists, either development or user list (where many devs also participate).  I guess if you were subscribed, you would have posted there to begin with, though.

(It's a sad fact ("sad," imho) that many developers never participate on forums, although there are a precious few who do.  For whatever reasons, they tend to prefer to use mailing lists.)

I'll try to dig up some info.  But since I don't have a clear understanding about these things, whatever I find might not be exactly on point.  But I'll try, and be back shortly 

Edit
But yes, indeed the gradient mesh is still considered experimental, even though some of the basic parts are working

[msdobrescu]

The published Adobe file format specifications are here: http://partners.adobe.com/public/developer/en/illustrator/sdk/AI7FileFormat.pdf

[brynn]

This is probably irrelevant, and you might already know about it anyway.  But just in case:
https://inkscape.org/en/learn/faq/#inkscape-edits-to-an-svg-file-which-was-originally-created-in-adobe-illustrator-are-lost-when-importing-back-into-ai  Apparently this URL was changed on the website - no idea why, but I hope whoever did it will realize the problems it can cause - such as this. 

The new link:  https://inkscape.org/en/learn/faq/#inkscape-edits-svg-file-which-was-originally-created-adobe-illustrator-are-lost-when-importing-back-ai

Here's a lot of info about gradient mesh and SVG2 standards:  http://tavmjong.free.fr/SVG/MESH/Mesh.html
and
https://svgwg.org/svg2-draft/pservers.html#MeshGradients

Here's everything in the bug tracker tagged for gradient mesh:  https://bugs.launchpad.net/inkscape/+bugs?field.tag=gradient-mesh  Might find more under different search terms.

Because Inkscape is an open source project, you'd be perfectly welcome to start a new report about your issue (if the existing ones don't already cover it)  In my experience, you really never know when something is going to spark the interest of a developer.  Here's some info about making a new "bug" report (bugs and feature requests are both handled in the bug tracker):  https://inkscape.org/en/contribute/report-bugs/.

Other members might be able to provide additional info.  And again, posting in either the development or users mailing list will surely get the best answers in this case.  (https://inkscape.org/en/community/mailing-lists/)

Sorry I can't really have a decdent discuaaion with you, about this.  It's just a l ittle beyond my abilities.

[msdobrescu]

Hi, thanks for your efforts, my post was rather informative than a question.
It is right, Adobe cheats with SVG and EPS too.
Inkscape is able to re-import an EPS as a vector. Illustrator is deceitful here as it doesn't. It simply renders a raster.
But what can we do? We can't change Adobe's way.
Inkscape should be the choice, not because it is free of charge, but it is open-minded.
Unfortunately third parties need Illustrator compatible EPS...
Should I add a request for adopting the limited to simple gradients, AI compatible, EPS export extension?

[brynn]

Oh, sorry for misunderstanding.

I think it's a valid point:  "third parties need Illustrator compatible EPS..."

But since I don't understand you clearly, it's hard to give advice about what to do.  I think it would be better if you discuss directly with developers.  You can do that on either the development mailing list or the users' mailing list.

Filing a bug report, is for a situation where you have a very specific issue, either a bug or a specific feature to request.  In this case, it sounds more like you either want or need a discussion about making Inkscape EPS compatible with Illustrator, and whether it should be native or not.  And the mailing list would be the best place for that. 

After you've had a discussion, you can decide whether it sounds like the developers are thinking like you, or thinking different.  Or it's possible that some developers agree with you, and others don't.  (I don't know what they think, but I'll be interested to learn.)  Or maybe there's already some kind of project being worked on, and I just haven't heard of it yet.

Anyway, if they are thinking like you, then you can make a feature request.  However, there's a chance the developers might say they don't think making AI compatible EPS should be a native feature.  If that's the result, maybe you could try and contact the author of that extension.  Maybe the author would be interested to extend it to gradient mesh or even more?

I'm pretty sure you can send a message to the list without subscribing to the list, but I'm not positive.

[msdobrescu]

I've posted here because people need to know what is the status, technically.
The problem is to reverse engineer, if allowed, the AI EPS files v8 to v10, because there is no official information on them, in order to get gradient meshes working properly after import in Illustator, when exported from other tools.
It is a shame.
As posted in Inkscape wikis, Adobe usually saves their format in EPS or SVG. They parse that so SVG seems unaltered by other tool for Illustrator.
It is a control strategy, in order to prevent tools like Inkscape to be used by their market target.
Inkscape is able to read a vector out of a pure vector EPS, but Illustrator simply creates a raster out of it.
If there was not this issue, I would have always used Inkscape. Exclusively.