Edit the Solder mask Normally, the solder mask will be created automatically by Sprint-Layout, and you don't have to care about this.Sprint-Layout is generating the solder mask by excluding all pads and SMD-pads from the mask, so that these areas are solderable. Sometimes it is necessary to extend this solder mask, e.g. if you want to tin a track. In this case you can edit the solder mask. Click on the Solder mask button in the left sidebar to enter the edit-mode for the solder mask: All elements which are "solderable" will be displayed in white. Normally this are all pads and SMD-pads. In this mode you can now add additional elements to the solder mask, by clicking on it. This element will added to the solder mask, and it will be displayed in white immediately. Vice versa, you can also exclude an element from the solder mask. Just click on a white element to exclude it. The element will displayed in his normal color immediately. You can reset the solder mask any time to the default setting (all pads and SMD-pads). To do this just select Reset solder mask... from the Extras menu.