Polyline doesn't match layer thickness despite thickness being set to "by layer"

[tgalanel]

As the title says, my line shows up thicker than it should based on the layer thickness (.15mm).

Please excuse me if this is a basic problem I am new and haven't been able to find the cause of this in days.

Attaching screenshots of line properties and layer properties. As well as the dwg file itself.

Thank you.

[Kent1Cooper · Accepted solution]

What you mean is lineweight, not thickness.  "Thickness" is up off the page in the Z direction.

Some of your Polylines have non-zero width, which will override the lineweight setting.  If you want the appearance to be controlled by the lineweight, make all Polylines have a global width of zero.  You can select them all collectively and fix that for all in the Properties palette:

And set the PLINEWID System Variable to zero, so that subsequently-drawn Polylines will have it that way.  That is set at 0.05 in the drawing as posted, and the Polylines I checked had that, so they were apparently drawn with that setting in place. 

[tgalanel]

Thank you! This worked