The positioning of the PCB data on the SMD-Stencil follows this standard:
A) Customer sends stencil data with included contour / data positioning:
The positioning of the customer is used.
B) Only the PCB-(panel)contour is available:
The stencil is centered on the PCB contour.
Advantage: The stencil covers the entire PCB
C) PCB-(panel)contour is not available:
The stencil is centered on the pads (paste data).
If your SMD-Stencil is to be manufactured deviating from the standard (e.g. centering the stencil on paste data with given board contour), please indicate this in the notes.
Standard layers for paste data / also recommended for stencil contour: