The default minimum and maximum values for the solder mask are 4 mil. Percentage values do not apply. The solder mask appears on layer 29 (SolderMaskTop) or layer 30 (SolderMaskBottom).
The default value for the stencil is 0, which matches the stencil dimensions to the Surface Mount Device (SMD). For Long, Offset, or Slot SMDs and pads, use the smaller dimension if values are in percent. These values are restricted by minimum and maximum limits. Stencil values are positive, but they reduce the stencil size. The stencil is generated only for SMDs and appears on layer 31 (StencilTop) or layer 32 (StencilBottom).
The Limit controls solder mask lacquer coverage on vias based on hole diameter. When Limit is 0, all vias receive a solder mask opening and are free of lacquer.
Example:
When Limit = 24:
All through-plated holes up to 24 mil diameter do not get a solder mask symbol; instead, they are lacquered. Vias with larger diameters get a solder mask symbol.
Note: To generate a solder mask for vias with hole diameters below the limit, set the Solder Mask flag (STOP) to ON in the Library Editor. Setting the solder mask or stencil (only for SMD) to OFF for a PTH pad or SMD pad in the Library Editor prevents Fusion from generating a solder mask or stencil for it.