Illustrator Hiccup

[Mysterio2099]

I've attached my .AI file (zipped).

This isn't a serious project, just messing around. I'm having a problem I've never seen before. Making a simple clipping mask, using the Layer 1 shape as the mask, the top of the masked area isn't completely covered. Some of the color from Layer 1 is showing.

Any help would be appreciated.

Thanks!

[Lukas Engqvist]

Strictly speaking you are not masking but hiding. There is a white object of similar form as the shape you are hiding. If you place an object behind you see the white form, so it is not a mask. A mask is a "window" revealing an object rather than one object hiding another.

Anti-aliasing problem. If you turn off Anti-aliasing in your preferences you no longer see the artifact. This is not an uncommon thing in PDF files, where there is a similar setting though there it is called "smooth line art" and "smooth images".

What happens is the software renders from bottom up. The blue shape is rendered and to give it a smooth appearance anti-aliased. The white object on top is also antialiased, but there is a mathematical where the one shape rounds up and the other rounds down giving the fine appearance of the non-existent edge. The edge is the same thickness irrespective of zoom level, this is a hint.

Also i see one very bad habit. In your document you have a green colour called "black 2" Call it what you will, but it is extreemly dangerous to have a green called black, because it may at some point in your workflow become black. Not critical unless it is spot colour but none the less a bad habit. (eg if it is placed in an indesign document that has a black colour called "Black 2" defined differently than your illustrator file)

[Mysterio2099]

Thanks for the help, Lukas. I know about the color names. I was using the green to make the mask. It wouldn't be in the final file. Either way, it's not for a major project.

Thanks again!