Bold, Soft Polish
Bold, Soft Polish chainrings are machined using larger drill bits when cutting the design. This allows the chainring to be stronger, and quicker to cut. The chainring has a soft polish so together with quicker production speeds allows the Bold version of the chainrings to be more affordable.
Technically Bold and Fine chainrings are exactly the same, it is only the design and the finish that is produced differently.The technical specifications of tooth width, profile, BCD and plate thickness etc. remain the same whether the chainring is Bold or Fine.