Solder Mask Over Traces When Rest Of Copper Layer Is Bare

[9V1MI]

I want bare copper on the front and back copper layers for heat sinking. How to ensure there is solder mask covering the traces?

[eelik]

If you want bare copper, you want to ensure there’s no solder mask covering the traces. Just add a graphic lines or polygons in the mask layer which covers those areas. The physical solder mask substance isn’t applied to those places where the KiCad’s mask layer is active.

[paulvdh]

You can show / hide the solder mask layers (Front & Back) in the Layers Manager:

Unlike (all?) other layers these are shown in negative. So everywhere you see the Purple / beige of the Solder Mask layers, the solder mask is removed.

If you want big cutouts in the solder mask to expose copper, you can select a Solder Mask layer (F. or B.) and then:

Pcbnew / Place / Polygon

to draw stuff on your solder mask layer.

In the “Layers Manager” you have a lot of controll on what’s visible on the screen. You can en/dis -able multiple layers by right clicking and selecting one of the options in the popup menu.
Look, I just drew a small cutout on the Front Soldermask layer:

[9V1MI]

Yah, I forgot that the solder mask is negative thinking, where it is it isn’t. I got my usage figured out. Thanks for your response.
–Larry