Finish line in acrylic jacket crown is:
Shoulder

It is a right-angled finish line.
Produces a wide ledge which resists compressive occlusal forces.
Requires more preparation, hence it is not conservative.
Indicated for ceramic restorations – all ceramic and metal ceramic (where ceramic forms the margin).
It is prepared using a flat-end tapering diamond. This is produced by sinking in the entire diamond into the tooth. The tip produces the shoulder while the sides give the necessary taper to the axial surface. End-cutting diamond is used to finish the shoulder. It has a cutting tip and noncutting sides.
Sharp internal line angle can produce stresses in all-ceramic crowns

Key Concept:
Finish line in acrylic jacket crown is butt shoulder ﬁnish line with 0.5 mm width around the entire  tooth.
Ref: Textbook of prosthodontics V Rangarajan Ed. 2nd
Shoulder
Shoulder with bevel
Radial shoulder
Exaggerated chamfer