Layers window, meaning of the circle on the right?

[pietera17573163]

In the layers window, sometimes the circle on the right is coloured in and sometimes not, what does this mean? And how do I change it so it is not coloured in as in the layer below. 

[Mylenium]

That is supposed to indicate different content types and how they interact with underlying layers. Blending modes, compound paths, knockout groups and such. Not really useful and most people barely take note of that.

Mylenium

[pietera17573163]

Thank you @Mylenium Reason I am asking is because I do all my artwork in illustratior, and whenever that circle is coloured in my printing software does not recocnise my cutting contour anymore. At least I have an idea of what it means now.

[Doug A Roberts]

It means there are appearance attributes applied to the layer. I would disagree with Mylenium that it is "not really useful"; it's very useful and important to check.

Click on it, then open the Appearance panel to see what's affecting the layer.

[Jeff Witchel, ACI]

Hmm! I'm wondering if you have Effects applied in the Appearance panel that your printer software does not understand. 

Try saving the file with a new name, then select the objects that are "colored in" in the Layers panel. And go to the Object menu > Expand Appearance. See it your contours are recognized and print now.

[Met1]

Your cutting contour shouldn't have effects applied to it, put it on a seperate layer then hide it while you are doing all your design work...

[Met1]

I find it useful, and, as usual, Adobe have it covered:

https://helpx.adobe.com/illustrator/using/layers.html