What do the concentric rectangles in Illustrator's layer visibility interface mean?

Question

I have created an image with multiple layers, paint groups, layer groups etc.

The image saves okay as .ai or even export to .png. However when i use the save for web feature my topmost layer group is missing from the image.

The only difference in this layer that I can see from any others, is that instead of the usual 'eye' icon in the layer visibility select, there is a solid rectangle with a border in this place.

Would someone please explain what this icon indicates, how it manipulated and whether it has any bearing on my Save to Web issue.

Many thanks

Answer 1

The solid rectangle rather than and eye icon indicates the layer is set to a Template layer. It should also be locked by default (but it can be unlocked) and the actual type for the layer name will be italic.

Template layers do not print or export.

To remove the template designation, double-click the Layer in the Layer Panel, or highlight the Layer and choose Options for [Layer Name] from the Layer Panel menu. Then uncheck "Template".