In mastering, or editing, Feathering is the art of adding small amounts at the frequencies adjoining the main one, rather than applying a large amount of EQ at a single frequency. This lowers the phase shift brought about when using analog EQs and results in a smoother sound. For example, instead of adding +3dB at 100Hz, you add +1.5dB at 100Hz and + .5dB at 80Hz and 120Hz. Most EQ’s work a little differently in this regard, so what may sound great on one model may not be best on another. Ultimately the benefits of this are determined by the operational characteristics of the EQ being used as well as the level of understanding the engineer has about how the EQ behaves and his/her ability to effectively utilize that knowledge in the adjustments.