Why Ai adds a thin black outline to the shape (with a solid fill colour) after adding a gradient fill (Appearance Panel) to it!
I have a shape with a fill (solid) colour (img 1), adding a gradient fill (blending mode: softlight) to it (img 2), then it adds a thin black outline to the shape!
I add a gradient (black and white, softlight) to change only the fill colour not the gradient attributes (if I decide to change the shape's colour, the shade is fixed, the fill colour changes).
Does that stay when you go to View > Preview on CPU?
Yes. At first I thought it's the GPU glitch (as always in Ai), but no! The problem is when you bring it in Ps and make it larger (as Smart Object) it gets worse.
Probably an antialiasing problem. If you turn off antialiasing, does it go away?
No. What's that?!
Please upload a demo file to Dropbox or the like.
I don't get a line when placing into PS at 300ppi or 72ppi.
Why scale it in PS when you can change the size in Illy and import at 100%...
"I don't get a line when placing into PS at 300ppi or 72ppi."
But I get!
"Why scale it in PS when you can change the size in Illy and import at 100%..."
Because I work on a project as small as I can (about 1 inch in Illy), then import it in Ps (sometimes for mockups or a raster effect). This thin line appears in Illy (that's my main problem, I don't have any problem with Ps). I think the engineers invented (!) SO (Smart Object) for such an easy solution (every time working on a project in Ps, you don't need to open Ai to change the size).
I found something more interesting! Ai export as PNG doesn't have this thin line, but export as JPG has!!! Thanks for such masterpiece and epic software engineering 👏🏻🥴
Probably because PNG supports transparency and JPEG doesn't.
But why create a simple gradient in such a complicated way?
A simple gradient and changing the Hue in Recolor Artwork will keep your shade and change the color.
"Probably because PNG supports transparency and JPEG doesn't."
Why does "enable transparency" hide the line, then?!! What does it mean?
My question is why Ai has to have such a problem. Why can't Ai add a gradient layer (in the appearance panel) to a solid colour layer without any artefacts/glitches?!
"But why create a simple gradient in such a complicated way?
A simple gradient and changing the Hue in Recolor Artwork will keep your shade and change the color."
It's not complicated! Every time I want to change the colour, no need to change the gradient, I just change the colour. The gradient isn't always a shade or in Multiply/... blend mode. The important thing here is to fix the gradient (attribute) and just change the base colour. I also do this method in Ps. I create artwork in black and white and add "Solid Color" or "Gradient" Adjustment Layer ("Clipping Mask" to the artwork). Because this makes it easy to change colour (or base colours).
Because anti-aliasing artefacts may become less visible when transparency is used.
I think a single gradient is less complicated than your method, but that's just me.
I for one am silly enough to (almost) always recommend PNG rather than JPEG for such artwork made as clearcut vector art for clarity/crispness, losslessness, and often smaller file size, whenever applicable; to get the colours right, you may wish/need to finalize by opening the PNG in PS (Photoshop) and attach the (missing) colour profile (such as sRGB) there.
Thanks. I always export as PNG (from Ai to Ps, when I finalise the work). I embed the sRGB (or any colour profile I need), and "Compress" to make it smaller. I am wondering such industry-standard software (in vector drawing) has such a ridiculous problem! Ai can't blend a gradient layer (attribute in Appearance Panel) with a solid colour layer!
I think Denying the Problem doesn't help to solve the issue! It has to be mathematically solved because Ai is all mathematic and has a solution! I bet!