Overlapping gradient sections create bitmapping when exported

[waynusmartinez]

Help! I’ve created a gradient colour fill path (outlined/expanded to mesh) in Illustrator (RGB). The path overlaps another path of the same type of fill just a different colour. It’s all crisp and sharp in Illustrator. When I export to PNG or PSD (pixel based apps) the ouline of the section that sits on a transparent background is anti-aliased, but where the paths intersect each other there is sharp satggered bitmapping, no anti-aliasing. Can this be rectified?

[Ton Frederiks]

What happens if you rasterize it in Illustrator?

[waynusmartinez]

You’re a legend Tom, that seems to have worked! Never used that option before but I’ll see if the client is happy with having multiple source files. Thanks again, W

[Ton Frederiks]

Good to hear that worked. Also worth trying is setting the Anti-aliasing method to Art Optimized when exporting.

[waynusmartinez]

Hi Ton, thanks for the previous info which worked very well for exporting. I now have a similar problem with the AI asset itself within a print test and wondered if you could shed any light on the problem. Reference attached.

The object itself is a continuous stroke which blends through different colours with the same start and end colour swatch, this is then expanded to a gradient mesh so we don’t get any section gaps when PDF’d. The asset is going to be used as a brand shape in an asset library which we would like to be scalable when placed in layout programs over images with transparency effects, so this can’t be rasterized. In the print test the overlapping sections create a bitmapped edge when output through a RIP for litho. Do you know any solutions to stop the bitmapping. I’m thinking that I may need to section off the graphic as a whole and recreate the gradient in different sections which would be an insane task as the gradient rotation is meant to flow with the curve of the original stroke. Has this confused you? It confuses me and I’m explaining it. Look forward to hearing from you. W

[Ton Frederiks]

What kind of RIP are you using?

Can you check in Window > Flattener Preview if the bitmapped area contains transparency. 

[waynusmartinez]

Hi Ton, we are testing the graphic with no transparency effect to use on solid colours (the problem still occurs in this instance) and with a variety of transparency effects over images, for instance Lighten, Colour Dodge and Screen to see how the graphics colours react with underlying images.

[waynusmartinez]

I think it has to do with the software not being able to handle two overlapping gradient meshes within the same compound shape. It seems a lot of work as it’s almost there but I may have to section off all the parts and manually create the gradients from scratch?