We had another thread somewhat related to the subject but thought we might benefit from a thread just focusing on the details rather than one that responded to a number of specific questions.
The transisition from black applied to the bottom of the hood to exterior body color is this first set of pictures. The edge was masked off around the edges of the hood in some fashion that created a soft edge of paint as a final result. Restorers often choose to use a thin foam tape so that the edge is not too soft since originally the edge appears to be sharper on the long smooth sections where there are no features that got in the way to a more soft (as if the tape was not stuck to the hood surface as well or jagged where the worker had some difficultly. This range is evident in the examples posted below from very very early examples to fairly late built cars.
Hope this helps other seeking to reproduce the factor look and practices
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